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Fibroblast activation protein (FAP) is an important antigen in the tumor microenvironment, which plays a crucial role in promoting extracellular matrix remodeling and tumor cell metastasis. A circulating form of soluble FAP has also been identified in the serum, becoming a biomarker for pan-cancer diagnosis and prognosis. However, the current peptide substrate-based enzymatic activity detection or antibody-dependent detection methods have been hindered by insufficient selectivity and complex operations, so it is valuable to develop effective nucleic acid aptamers as FAP affinity ligands. In order to deeply explore the biomimetic recognition technology, this study proposed an elaborate aptamer screening strategy for targeting the protein characteristic structure. Taking the glycosylation of the FAP protein as a target, four FAP-specific aptamers with high performance were successfully generated. Further, using the champion aptamer as a recognition tool and combining it with ultrasensitive detection technology-surface enhanced Raman scattering (SERS), a novel dual aptamer-based sandwich sensor was constructed for the rapid determination of FAP. Due to the dual-specific recognition of the orthogonal aptamer pair, the sandwich method obviously improved the selectivity to FAP protein, with a maximum cross-reactivity of less than 8% and a quantitation limit of 100 pg/mL. It was conveniently applied in high-sensitive and high-selective detection of serum FAP in cancer patient samples. Therefore, the research of this study not only opens new access for the selection of antiglycan aptamers but also boosts the application of the FAP aptamer as a recognition tool in cancer diagnostics.

Ultrasensitive and population-scale cancer screening technologies are critical to reducing cancer mortality. However, the current qRT-PCR falls short in high-throughput screening of multiple cancers. Here, a rotavirus-inspired multicancer diagnosis system (RMDS) is developed via nanointerface engineering. RMDS employs Y-shaped DNA (YDNA) probes to encircle the graphene quantum dots (GQDs) for nanointerface modification. The biotransduction mechanisms at the nanointerface are systematically investigated. RMDS greatly enhances the transduction efficiency of biological analytes by optimizing the probe density and configuration. RMDS realizes ultrasensitive detection of the lung cancer KARS G12D mutation with a limit of detection (LoD) of 5.7 aM and the breast cancer-related AKT2 gene (LoD: 3.0 aM). The multiple chambers enable simultaneous diagnosis of multiple cancers and determination of cancer progression. Clinical validation shows RMDS can be a practical solution, which could complement or replace qRT-PCR and become the next-generation all-in-one tool for large-scale population cancer screening.

Cancer has emerged as a global health crisis, claiming millions of lives annually. Dendrimers and dendronized nanoparticles, a novel class of nanoscale molecules with highly branched three-dimensional macromolecular structures, have gained significant attention in cancer treatment and diagnosis due to their unique properties. These dendritic macromolecules offer a precisely controlled branching architecture, enabling functionalization with specific targeting molecules to enhance the selective delivery of therapeutic agents to tumor cells while minimizing systemic toxicity. Through surface modifications and the incorporation of various components, dendrimers demonstrate remarkable adaptability as nanocarriers for biomedical imaging and theranostic applications. Surface functionalization strategies, including PEGylation and ligand attachment (e.g., folic acid, RGD peptide, lactobionic acid), further enhance biocompatibility and facilitate targeted tumor cell imaging. Leveraging their improved biocompatibility and target specificity, dendritic nanosystems offer heightened sensitivity and precision in cancer diagnostics. Notably, the encapsulation of metal nanoparticles within dendrimers, such as gold nanoparticles, has shown promise in enhancing tumor imaging capabilities. Ongoing advancements in nanotechnology are poised to increase the sophistication and complexity of dendrimer-based systems, highlighting their potential as nanocarriers in drug delivery platforms, with a growing number of clinical trials on the horizon. This review provides a comprehensive overview of the potential and future prospects of dendrimers and dendrimer-based nanocarriers in targeted cancer therapy and diagnosis, exploring their ability to enhance biocompatibility, reduce toxicity, and improve therapeutic outcomes across various malignancies.

Biomarker discovery and application are paramount for the early diagnosis, treatment, and prognosis assessment of diseases. Novel proteomic strategies have been developed for high-efficiency biomarker screening. However, evaluating various strategies and applying them for the in-depth mining of biomarkers from blood need to be elucidated. Herein, we systematically evaluated the technical characteristics of three representative biomarker discovery strategies, including the most popular DIA proteomics, and two promising strategies targeting the cancer-secreted proteome or extracellular vesicle proteome, and integrated them into one multidimensional serum proteomic strategy. The results showed that the three strategies each have unique characteristics in terms of sensitivity, reproducibility, and protein coverage and are highly complementary in biomarker discovery. The integrated multidimensional serum proteomic strategy achieves deep and comprehensive coverage of the serum proteome, discovers more cancer markers, and helps achieve a more accurate multicancer (breast, lung, stomach, liver, and colorectum) diagnosis with 87.5% localization accuracy.

As medical advancements turn most cancers into manageable chronic diseases, new challenges arise in cancer recurrence monitoring. Detecting circulating tumor cells (CTCs) is crucial for monitoring cancer recurrence, but the current methods are cumbersome and costly. This study developed a new CTC detection system combining DNA aptamer recognition, hybridization chain reaction (HCR) technology, and DNA logic devices, enabling the one-step recognition of CTCs by identifying multiple membrane proteins. After catalytically active Au nanoparticles were attached through reduction synthesis in situ onto the DNA hybridization strands of the CTCs surface, a 3,3',5,5'-tetramethylbenzidine (TMB) colorimetric reaction was used to detect CTCs concentration via peroxidase-like catalysis. With this CTCs detection reporting system, we achieved an LOD of 4 cells/mL using an ultraviolet-visible (UV-vis) spectrophotometer. At certain concentrations, CTCs could even be detected visually without the need for an instrument. The development of this CTCs detection reporting system provided a convenient, reliable, and cost-effective detection strategy for widespread CTCs-based cancer recurrence monitoring.

Metal nanoparticles with inherent defects can harness biomolecules to catalyze reactions within living organisms, thereby accelerating the advancement of multifunctional diagnostic and therapeutic technologies. In the quest for superior catalytic efficiency and selectivity, atomically dispersed single-atom nanozymes (SANzymes) have garnered significant interest recently. This review concentrates on the development of SANzymes, addressing potential challenges such as fabrication strategies, surface engineering, and structural characteristics. Notably, we elucidate the catalytic mechanisms behind some key reactions to facilitate the biomedical application of SANzymes. The diverse biomedical uses of SANzymes including in cancer therapy, wound disinfection, biosensing, and oxidative stress cytoprotection are comprehensively summarized, revealing the link between material structure and catalytic performance. Lastly, we explore the future prospects of SANzymes in biomedical fields.

Extracellular vesicles (EVs) harbor abundant glycans that mediate various functions, such as intercellular communication and disease advancement, which play significant roles in disease progression. However, the presence of EV heterogeneity in body fluids and the complex nature of the glycan structures have posed challenges for the detection of EV glycans. In this study, we provide a streamlined method integrated, me mbrane- s pecific s eparation with lectin-induced ag gr e gation strategy (MESSAGE), for multiplexed profiling of EV glycans. By leveraging a rationally designed lectin-induced aggregation strategy, the expression of EV glycans is converted to size-based signals. With the assistance learning machine algorithms, the MESSAGE strategy with high sensitivity, specificity, and simplicity can be used for early cancer diagnosis and classification, as well as monitoring cancer metastasis via 20 μL plasma sample within 2 h. Furthermore, our platform holds promise for advancing the field of EV-based liquid biopsy for clinical applications, opening new possibilities for the profiling of EV glycan signatures in various disease states.

Accurate diagnosis of highly aggressive and deadly tumors is essential for effective treatment and improved patient outcomes, and microRNAs (miRNAs) have emerged as crucial biomarkers for their roles in tumor initiation, progression, and metastasis. Herein, we present an on-site visualization colorimetric assay for tumor-associated miRNAs using ruthenium nanoparticle decorated titanium dioxide nanoribbon (Ru@TiO 2 ) as a peroxidase-like (POD) nanozyme. Remarkably, the Ru@TiO 2 nanozyme can catalyze the oxidation of chromogenic substrates through its POD-like activity, which is effectively inhibited by pyrophosphate generated during the rolling circle amplification process, thereby enabling miRNA detection through a visible colorimetric readout. This approach provides a highly sensitive and specificity assay for miRNAs in diluted human serum with a detection limit of 100 pM. It shows great potential for clinical diagnostics and biological research, offering a promising tool for early cancer diagnosis and molecular diagnostics.

Cancer, which is characterized by high mortality rates, poses a significant threat to global human health. Early diagnosis is of paramount importance in managing cancer, and tumor markers have emerged as crucial indicators for achieving this goal. The advent of precision medicine has further emphasized the need for the effective detection of these markers. However, traditional detection methods are hampered by numerous limitations. In recent years, nanopore technology has emerged as a promising alternative, due to its unique physical and chemical properties, which facilitate rapid, label-free, and amplification-free detection. This Review focuses on the direct detection of tumor markers through nucleic acid analysis and indirect detection mediated by nucleic acids and facilitated by biological nanopores. Furthermore, it also discusses the challenges and prospects of applying biological nanopore sensing technology in early cancer diagnosis, underscoring its potential to revolutionize tumor marker detection.

Because of their unique electromechanical coupling response, piezoelectric smart biomaterials demonstrated distinctive capability toward effective, efficient, and quick diagnosis and treatment of a wide range of diseases. Such materials have potentiality to be utilized as wireless therapeutic methods with ultrasonic stimulation, which can be used as self-powered biomedical devices. An emerging advancement in the realm of personalized healthcare involves the utilization of piezoelectric biosensors for a range of therapeutic diagnosis such as diverse physiological signals in the human body, viruses, pathogens, and diseases like neurodegenerative ones, cancer, etc. The combination of piezoelectric nanoparticles with ultrasound has been established as a promising approach in sonodynamic therapy and piezocatalytic therapeutics and provides appealing alternatives for noninvasive treatments for cancer, chronic wounds, neurological diseases, etc. Innovations in implantable medical devices (IMDs), such as implantable piezoelectric energy generator (iPEG), offer significant advantages in improving physiological functioning and ability to power a cardiac pacemaker and restore the heart function. This comprehensive review critically evaluates the role of piezoelectricity in disease diagnosis and treatment, highlighting the implication of piezoelectric smart biomaterials for biomedical devices. It also discusses the potential of piezoelectric materials in healthcare monitoring, tissue engineering, and other medical applications while emphasizing future trends and challenges in the field.

Tumor-associated antigens (TAAs) are not exclusively expressed in cancer cells, inevitably causing the "on target, off tumor" effect of molecular recognition tools. To achieve precise recognition of cancer cells, by using protein tyrosine kinase 7 (PTK7) as a model TAA, a DNA molecular logic circuit Aisgc8 was rationally developed by arranging H + -binding i-motif, ATP-binding aptamer, and PTK7-targeting aptamer Sgc8c in a DNA sequence. Aisgc8 output the conformation of Sgc8c to recognize PTK7 on cells in a simulated tumor microenvironment characterized by weak acidity and abundant ATP, but not in a simulated physiological environment. Through in vitro and in vivo results, Aisgc8 demonstrated its ability to precisely recognize cancer cells and, as a result, displayed excellent performance in tumor imaging. Thus, our studies produced a simple and efficient strategy to construct DNA logic circuits, opening new possibilities to develop convenient and intelligent precision diagnostics by using DNA logic circuits.

Tumor-derived small extracellular vesicle (sEV) microRNAs (miRNAs) are emerging biomarkers for cancer diagnostics. Conventional sEV miRNA detection methods necessitate the lysis of sEVs, rendering them laborious and time-consuming and potentially leading to damage or loss of miRNAs. Membrane fusion-based in situ detection of sEV miRNAs involves the preparation of probe-loaded vesicles ( e.g. , liposomes or cellular vesicles), which are typically sophisticated and require specialist equipment. Membrane perforation methods employ chemical treatments that can induce severe miRNA degradation or leaks. Inspired by previous studies that loaded nucleic acids into EVs or cells using hydrophobic tethers for therapeutic applications, herein, we repurposed this strategy by conjugating a hydrophobic tether onto molecular beacons to aid their transportation into sEVs, allowing for in situ detection of miRNAs in a fusion-free and multiplexing manner. This method enables simultaneous detection of multiple miRNA species within serum-derived sEVs for the diagnosis of prostate cancer, breast cancer, and gastric cancer with an accuracy of 83.3%, 81.8%, and 100%, respectively, in a cohort of 66 individuals, indicating that it holds a high application potential in clinical diagnostics.

As an important biomarker, tumor cell-derived exosomes have substantial application prospects in early cancer screening and diagnosis. However, the unsatisfactory sensitivity and complicated sample pretreatment processes of conventional detection approaches have limited their use in clinical diagnosis. Nanopore sensors, as a highly sensitive, label-free, single-molecule technology, are widely utilized in molecule and bioparticle detection. Nevertheless, the exosome capture rate through nanopores is extremely low due to the low surface charge densities of exosomes and the effects of electrolyte concentration on their structural stability, thereby reducing the detection throughput. Here, we report an approach to improve the capture rate of exosome translocations using silicon nitride (SiN x ) nanopores assisted by a slight salt electrolyte gradient. Improvements in exosome translocation event frequency are assessed in electrolyte solutions with different concentration gradients. In the case of asymmetric electrolytes ( cis 1× PBS and trans 0.2 M NaCl, 1× PBS ), the event frequency of tumor cell (HepG2)-derived exosome translocations is enhanced by nearly 2 orders of magnitude while maintaining vesicle structure stability. Furthermore, benefiting from the salt gradient effect, tumor cell (AsPC-1 and HCT116)-derived exosome translocations could be discriminated from those of HepG2 cell-derived exosomes. The developed highly sensitive detection method for tumor cell-derived exosomes at the single-particle level provides an approach for early cancer diagnosis.

Early cancer detection is crucial for effective treatment, but current methods have limitations. Novel biomaterials, such as hydrogels, offer promising alternatives for developing biosensors for cancer detection. Hydrogels are three-dimensional and cross-linked networks of hydrophilic polymers that have properties similar to biological tissues. They can be combined with various biosensors to achieve high sensitivity, specificity, and stability. This review summarizes the recent advances in hydrogel-based biosensors for cancer detection, their synthesis, their applications, and their challenges. It also discusses the implications and future directions of this emerging field.

Accurately distinguishing tumor cells from normal cells is a key issue in tumor diagnosis, evaluation, and treatment. Fluorescence-based immunohistochemistry as the standard method faces the inherent challenges of the heterogeneity of tumor cells and the lack of big data analysis of probing images. Here, we have demonstrated a machine learning-driven imaging method for rapid pathological diagnosis of five types of cancers (breast, colon, liver, lung, and stomach) using a perovskite nanocrystal probe. After conducting the bioanalysis of survivin expression in five different cancers, high-efficiency perovskite nanocrystal probes modified with the survivin antibody can recognize the cancer tissue section at the single cell level. The tumor to normal (T/N) ratio is 10.3-fold higher than that of a conventional fluorescent probe, which can successfully differentiate between tumors and adjacent normal tissues within 10 min. The features of the fluorescence intensity and pathological texture morphology have been extracted and analyzed from 1000 fluorescence images by machine learning. The final integrated decision model makes the area under the receiver operating characteristic curve (area under the curve) value of machine learning classification of breast, colon, liver, lung, and stomach above 90% while predicting the tumor organ of 92% of positive patients. This method demonstrates a high T/N ratio probe in the precise diagnosis of multiple cancers, which will be good for improving the accuracy of surgical resection and reducing cancer mortality.

G-quadruplex (G4), an unconventional nucleic acid structure, shows polymorphism in its topological morphology. The parallel G4 topology is the most prevalent form in organisms and plays a regulatory role in many biological processes. Designing fluorescent probes with high specificity for parallel G4s is important but challenging. Herein, a supramolecular assembly of the anionic cyanine dye SCY-5 is reported, which selectively identifies parallel G4 topology. SCY-5 can clearly distinguish parallel G4s from other G4s and non-G4s, even including hybrid-type G4s with parallel characteristics. The high specificity mechanism of SCY-5 involves a delicate balance between electrostatic repulsion and π-π interaction between SCY-5 and G4s. Using SCY-5, cellular RNA extracted from peripheral venous blood was quantitatively detected, and a remarkable increase in RNA G4 content in cancer patients compared to healthy volunteers was confirmed for the first time. This study provides new insights for designing specific probes for parallel G4 topology and opens a new path for clinical cancer diagnosis using RNA G4 as a biomarker.

Abnormal expression in long noncoding RNAs (lncRNAs) is closely associated with cancers. Herein, a novel CRISPR/Cas13a-enhanced photocurrent-polarity-switching photoelectrochemical (PEC) biosensor was engineered for the joint detection of dual lncRNAs, using deep learning (DL) to assist in cancer diagnosis. After target lncRNA-activated CRISPR/Cas13a cleaves to induce DNAzyme bidirectional walkers with the help of cofactor Mg 2+ , nitrogen-doped carbon-Cu/Cu 2 O octahedra are introduced into the biosensor, producing a photocurrent in the opposite direction of CdS quantum dots (QDs). The developed PEC biosensor shows high specificity and sensitivity with limits of detection down to 25.5 aM for lncRNA HOTAIR and 53.1 aM for lncRNA MALAT1. More importantly, this platform for the lncRNA joint assay in whole blood can successfully differentiate cancers from healthy people. Furthermore, the DL model is applied to explore the potential pattern hidden in data of the established technology, and the accuracy of DL cancer diagnosis can acquire 93.3%. Consequently, the developed platform offers a new avenue for lncRNA joint detection and early intelligent diagnosis of cancer.

Early detection of cancer is vital for increasing patient survivability chances. The three major techniques used to diagnose cancers are instrumental examination, tissue biopsy, and tumor biomarker detection. Circulating tumor DNA (ctDNA) has gained much attention in recent years due to advantages over traditional technology, such as high sensitivity, high specificity, and noninvasive nature. Through the mechanism of apoptosis, necrosis, and circulating exosome release in tumor cells, ctDNA can spread throughout the circulatory system and carry modifications such as methylations, mutations, gene rearrangements, and microsatellite instability. Traditional gene-detection technology struggles to achieve real-time, low-cost, and portable ctDNA measurement, whereas electrochemical biosensors offer low cost, high specificity alongside sensitivity, and portability for the detection of ctDNA. Therefore, this review focuses on describing the recent advancements in ctDNA biomarkers for various cancer types and biosensor developments for real-time, noninvasive, and rapid ctDNA detection. Further in the review, ctDNA sensors are also discussed in regards to their selections of probes for receptors based on the electrode surface recognition elements.

Extremely small iron oxide nanoparticle (ESIONP)-based stimuli-responsive switchable MRI contrast agents (CAs) show great promise for accurate detection of tumors due to their outstanding advantages of high specificity and low background signal. However, currently developed ESIONP-based switchable CAs often suffer single-biomarker-induced responses, which lack absolute specificity to pathological tissues, potentially diminishing diagnostic accuracy. In this study, weak acidity and hypoxia, two of the most remarkable characteristics of tumors, are introduced as dual biomarker stimuli to construct an ESIONP-based switchable MRI CA (DKL-CA), with its signal switch controlled by a "dual-key-and-lock" strategy. Only when DKL-CA is exposed to a coexisting weakly acidic and hypoxic environment can monodispersed ESIONPs form nanoclusters, thereby realizing a switch from the T 1 to T 2 contrast. Moreover, DKL-CA exhibits favorable biosafety and the capacity for precise tumor diagnosis in tumor-bearing mice. Overall, DKL-CA paves the way for designing highly accurate ESIONP-based MRI CAs for tumor diagnosis.

Near-infrared (NIR) luminescent lanthanide materials hold great promise for bioanalysis, as they have anti-interference properties. The approach of efficient luminescence is sensitization through a reasonable chromophore to overcome the obstacle of the aqueous phase. The involvement of the surfactant motif is an innovative strategy to arrange the amphiphilic groups to be regularly distributed near the polymer to form a closed sensitized space. Herein, a lanthanide polymer (TCPP-PEI 70K -FITC@Yb/SDBS) is designed in which the meso-tetra(4-carboxyphenyl)porphine (TCPP) ligand serves as both a sensitizer and photocatalytic switch. The surfactant sodium dodecyl benzenesulfonate (SDBS) wraps the photosensitive polymers to form a hydrophobic layer, which augments the light-harvesting ability and expedites its photocatalysis. TCPP-PEI 70K -FITC@Yb/SDBS is subsequently applied as an amplified photocatalysis toolbox for universally regulating the generation of reactive oxygen species (ROS). Boosting 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to produce blue products, a dual-mode biosensor is fabricated for improving the diagnosis of programmed death ligand-1-positive (PDL1) cancer exosomes. Exosomes were captured by Fe 3 O 4 modified by the PDL1 aptamer, enabling replacement of alkaline phosphatase (ALP)-labeled multiple hybridized chains; then, the isolated ALP triggered a hydrolysis reaction to block the generation of oxTMB. Detection sensitivity improves by 1 order of magnitude through SDBS modulation, down to 10 4 particles/mL. The sensor performed well clinically in distinguishing cancer patients from healthy individuals, expanding physiological applications of near-infrared lanthanide luminescence.

The traditional recognition of extracellular matrix (ECM) at tissue sections relies on the time-consuming immunofluorescence that could not meet the demand of rapid diagnosis. Herein, we introduce a thickness-resolved electrochemiluminescence (ECL) microscopy to image thin-layer ECM at tissue sections for fast histopathological analysis. The unique surface-confined ECL mechanism enables to unveil the diversity and complexity of multiple tissue structures with varying thicknesses. Notably, the short lifetimes and the limited diffusion of electrogenerated coreactant radicals combined with their chemical reactivity result in a 2-fold increase in ECL intensity on ECM structures compared to the remaining tissue, enabling ECM visualization without specific labeling. The further quantitation of the ECM localization within tissue sections furnishes crucial insights into tumor progression and, more importantly, differentiates carcinoma and paracancerous tissues from patients in less than 30 min. Moreover, the reported electrochemistry-based microscopy is a dynamic approach allowing to investigate the transport, tortuosity, and trafficking properties through the tissues. This thickness-resolved recognition strategy not only opens new avenues for imaging complex samples but also holds promise for expediting tissue pathologic diagnosis, offering a more automated protocol with enhanced quantitative data compared to current intraoperative pathology methods.

The identification and detection of disease-related biomarkers is essential for early clinical diagnosis, evaluating disease progression, and for the development of therapeutics. Possessing the advantages of high sensitivity and selectivity, fluorescent probes have become effective tools for monitoring disease-related active molecules at the cellular level and in vivo . In this review, we describe current fluorescent probes designed for the detection and quantification of key bioactive molecules associated with common diseases, such as organ damage, inflammation, cancers, cardiovascular diseases, and brain disorders. We emphasize the strategies behind the design of fluorescent probes capable of disease biomarker detection and diagnosis and cover some aspects of combined diagnostic/therapeutic strategies based on regulating disease-related molecules. This review concludes with a discussion of the challenges and outlook for fluorescent probes, highlighting future avenues of research that should enable these probes to achieve accurate detection and identification of disease-related biomarkers for biomedical research and clinical applications.

Accurately assaying tumor-derived circulating extracellular vesicles (EVs) is fundamental in noninvasive cancer diagnosis and therapeutic monitoring but limited by challenges in efficient EV isolation and profiling. Here, we report a bioinspired buoyancy-driven metal-organic framework (MOF) corona that leverages on-bubble coordination and dual-encoded surface-enhanced Raman scattering (SERS) nanotags to streamline rapid isolation and ultrasensitive profiling of plasma EVs in a single assay for cancer diagnostics. This integrated bubble-MOF-SERS EV assay (IBMsv) allows barnacle-like high-density adhesion of MOFs on a self-floating bubble surface to enable fast isolation (2 min, near 90% capture efficiency) of tumor EVs via enhanced EV-MOF binding. Also, IBMsv harnesses four-plexed SERS nanotags to profile the captured EV surface protein markers at a single-particle level. Such a sensitive assay allows multiplexed profiling of EVs across five cancer types, revealing heterogeneous EV surface expression patterns. Furthermore, the IBMsv assay enables cancer diagnosis in a pilot clinical cohort ( n = 55) with accuracies >95%, improves discrimination between cancer and noncancer patients via an algorithm, and monitors the surgical treatment response from hepatocellular carcinoma patients. This assay provides a fast, sensitive, streamlined, multiplexed, and portable blood test tool to enable cancer diagnosis and response monitoring in clinical settings.

Various nanomaterials have recently become fascinating tools in cancer diagnostic applications because of their multifunctional and inherent molecular characteristics that support efficient diagnosis and image-guided therapy. Zein nanoparticles are a protein derived from maize. It belongs to the class of prolamins possessing a spherical structure with conformational properties similar to those of conventional globular proteins like ribonuclease and insulin. Zein nanoparticles have gained massive interest over the past couple of years owing to their natural hydrophilicity, ease of functionalization, biodegradability, and biocompatibility, thereby improving oral bioavailability, nanoparticle targeting, and prolonged drug administration. Thus, zein nanoparticles are becoming a promising candidate for precision cancer drug delivery. This review highlights the clinical significance of applying zein nanosystems for cancer theragnostic─moreover, the role of zein nanosystems for cancer drug delivery, anticancer agents, and gene therapy. Finally, the difficulties and potential uses of these NPs in cancer treatment and detection are discussed. This review will pave the way for researchers to develop theranostic strategies for precision medicine utilizing zein nanosystems.

In this work, we present an array-based chemical nose sensor that utilizes a set of ensemble-modified aptamer (EMAmer) probes to sense subtle physicochemical changes on the cell surface for cancer cell identification. The EMAmer probes are engineered by domain-selective incorporation of different types and/or copies of positively charged functional groups into DNA scaffolds, and their differential interactions with cancer cells can be transduced through competitive adsorption of fluorophore-labeled EMAmer probes loaded on MoS 2 nanosheets. We demonstrate that this MoS 2 -EMAmer-based sensor array enables rapid and effective discrimination among six types of cancer cells and their mixtures with a concentration of 10 4 cells within 60 min, achieving a 94.4% accuracy in identifying blinded unknown cell samples. The established MoS 2 -EMAmer sensing platform is anticipated to show significant promise in the advancement of cancer diagnostics.

As a tumor-suppressing protein, p53 plays a crucial role in preventing cancer development. Its utility as an early cancer detection tool is significant, potentially enabling clinicians to forestall disease advancement and improve patient prognosis. In response to the pathological overexpression of this antigen in tumors, the prevalence of anti-p53 antibodies increases in serum, in a manner quantitatively indicative of cancer progression. This spike can be detected through techniques, such as Western blotting, immunohistochemistry, and immunoprecipitation. In this study, we present an electrochemical approach that supports ultrasensitive and highly selective anti-p53 autoantibody quantification without the use of an immuno-modified electrode. We specifically employ antigen-mimicking and antibody-capturing peptide-coated magnetic nanoparticles, along with an AC magnetic field-promoted sample mixing, prior to the presentation of Fab-captured targets to simple lectin-modified sensors. The subfemtomolar assays are highly selective and support quantification from serum-spiked samples within minutes.

With the emergence of microRNA (miRNA) as a promising biomarker in cancer diagnosis, it is significant to develop multiple analyses of miRNAs. However, it still faces difficulties in ensuring the sensitivity and accuracy during multiplex detection owing to the low abundance and experimental deviation of miRNAs. In this work, a flexible-arranged biomimetic array integrated with parallel entropy-driven circuits (EDCs) was developed for ultrasensitive, multiplex, reliable, and high-throughput detection of miRNAs. The biomimetic array was fabricated by arrangement of various photonic crystals (PCs) for adjustable photonic band gaps (PBGs) and specific fluorescence enhancement. Meanwhile, two cancer-related miRNAs and one reference miRNA were introduced as multiple analytes as a proof-of-concept. The parallel EDCs with negligible crosstalk were designed based on the modular property. Because of the one-to-one match between the emitted fluorescence of parallel EDCs and the PBGs of the flexible-arranged biomimetic array, the generated fluorescence signal triggered by target miRNAs can be enhanced on the corresponding domain of the array. Furthermore, the amplified signal of the array was detected with high-throughput scanning, which could reveal specific information on cancer-related miRNAs as well as reference miRNA, enhancing the abundance and reliability of the analysis. The proposed array has the merits of a modular design, flexible deployment, simple operation (nonenzymatic and isothermal), improved accuracy, high sensitivity, and multiplex analysis, showing potential in disease diagnosis.

As an important component of highly heterogeneous exosomes, exosomal microRNAs (miRNAs) have great potential as noninvasive biomarkers for cancer diagnosis. Therefore, a sensitive and simple sensor is the key for its clinical application. Herein, we designed an exponential amplification reaction (EXPAR) to induce the reactivation of the CRISPR-associated protein 9/small guide RNA (Cas9/sgRNA) complex, thus achieving sensitive and visual exosomal miRNAs-21 (miR-21) fluorescence sensing. In this design, we inactivated the sgRNA by hybridizing sgRNA and blocker DNA. Then, we used a trigger DNA to hybridize with miR-21 and produced a lot of activated DNA by EXPAR. Those activated DNA further hybridized with blocker DNA and released the free sgRNA to form the activated Cas9/sgRNA complex. Based on the quick cleavage of activated Cas9/sgRNA complex, the reporter DNA labeled by SYBR Green I was released from the surface of the magnetic nanoparticles (MNPs) into the supernatant, and thus was used to sensitively quantify the miRNAs concentration with a limit of detection of 3 × 10 3 particles/mL. In addition, this fluorescence sensor has also been successfully employed to distinguish healthy people and cancer patients by naked-eye observation of the fluorescence, thus demonstrating its great potential for accurate and point-of-care cancer diagnosis.

Liquid biopsies have caused a significant revolution in cancer diagnosis, and the use of point of care (PoC) platforms has the potential to bring liquid biopsy-based cancer detection closer to patients. These platforms provide rapid and on-site analysis by reducing the time between sample collection and results output. The aim of this tutorial content is to provide readers an in-depth understanding regarding the choice of the ideal sensing platform suitable for specific cancer-related biomarkers.

Cancer-related extracellular vesicles (EVs) are considered important biomarkers for cancer diagnosis because they can convey a large amount of information about tumor cells. In order to detect cancer-related EVs efficiently, an electrochemiluminescence (ECL) sensor for the specific identification and highly sensitive detection of EVs in the plasma of cancer patients was constructed based on dual recognitions by glycosyl-imprinted polymer (GIP) and aptamer. The characteristic glycosyl Neu5Ac-α-(2,6)-Gal-β-(1-4)-GlcNAc trisaccharide on the surface of EVs was used as a template molecule and 3-aminophenylboronic acid as a functional monomer to form a glycosyl-imprinted polymer by electropolymerization. After glycosyl elution, the imprinted film specifically recognized and adsorbed the EVs in the sample, and then the CD63 aptamer-bipyridine ruthenium (Aptamer-Ru(bpy)) was added to combine with the CD63 glycoprotein on the extracellular vesicle's surface, thus providing secondary recognition of the EVs. Finally, the EVs were quantitatively detected according to the ECL signal produced by the labeled bipyridine ruthenium. When more EVs were captured by the imprinted film, more probes were obtained after incubation, and the ECL signal was stronger. Under the optimized conditions, the ECL signal showed a good linear relationship with the concentration of EVs in the range of 9.5 × 10 2 to 9.5 × 10 7 particles/mL, and the limit of detection was 641 particles/mL. The GIP sensor can discriminate between the EV contents of cancer patients and healthy controls with high accuracy. Because of its affordability, high sensitivity, and ease of use, it is anticipated to be employed for cancer early detection and diagnosis.

Liquid biopsy is of great significance in tumor early diagnosis and treatment stratification. PD-L1-positive small extracellular vesicles (PD-L1 + sEVs) are closely related to tumor growth and immunotherapy response, which are considered valuable liquid biopsy biomarkers. In contrast to conventional in vitro detection, in vivo detection has the ability to improve the detection efficiency and enable continuous or real-time dynamic monitoring. However, in vivo detection of PD-L1 + sEVs has multiple difficulties, such as high cell background, complex blood environments, and lack of a specific and stable detection method. Herein, the in vivo detection of PD-L1 + sEVs method was constructed, which efficiently separated sEVs based on the microfluidic device and quantitatively analyzed PD-L1 + sEVs by aptamer recognition and hybridization chain reaction. The concentration of PD-L1 + sEVs was continuously monitored, and significant differences at different stages of tumor as well as a correlation with tumor volume were found. Diseased and healthy individuals could also be effectively distinguished based on the concentration of PD-L1 + sEVs. The method with good stability, biocompatibility, and detection performance provided a powerful means for in vivo detection of PD-L1 + sEVs, contributing to the clinical diagnosis and treatment of tumor.

Strategies for rapid, effective nucleic acid processing hold tremendous significance to the clinical analysis of circulating tumor DNA ( ctDNA ), a family of important markers indicating tumorigenesis and metastasis. However, traditional techniques remain challenging to achieve efficient DNA enrichment, further bringing about complicated operation and limited detection sensitivity. Here, we developed an ion concentration polarization microplatform that enabled highly rapid, efficient enrichment and purification of ctDNA from a variety of clinical samples, including serum, urine, and feces. The platform demonstrated efficiently separating and enriching ctDNA within 30 s, with a 100-fold improvement over traditional methods. Integrating an on-chip isothermal amplification module, the platform further achieved 100-fold enhanced sensitivity in ctDNA detection, which significantly eliminated false-negative results in the serum or urine samples due to the low abundance of ctDNA . Such a simple-designed platform offers a user-friendly yet powerful diagnosis technique with a wide applicability, ranging from early tumor diagnosis to infection screening.

Infrared (IR) spectroscopy of serum/plasma represents an alluring molecular diagnostic tool, especially for cancer, as it can provide a molecular fingerprint of clinical samples based on vibrational modes of chemical bonds. However, despite the superior performance, the routine adoption of this technique for clinical settings has remained elusive. This is due to the potential confounding factors that are often overlooked and pose a significant barrier to clinical translation. In this Perspective, we summarize the concerns associated with various confounding factors, such as fluid sampling, optical effects, hemolysis, abnormal cardiovascular and/or hepatic functions, infections, alcoholism, diet style, age, and gender of a patient or normal control cohort, and improper selection of numerical methods that ultimately would lead to improper spectral diagnosis. We also propose some precautionary measures to overcome the challenges associated with these confounding factors.

The lateral flow immunoassay (LFIA) is a sought-after point-of-care testing platform, yet the insufficient sensitivity of the LFIA limits its application in the detection of tumor biomarkers. Here, a colorimetric signal amplification method, bimetallic nanozyme-mediated in situ-catalyzed reporter deposition (BN-ISCRD), was designed for ultrasensitive cancer diagnosis. The bimetallic nanozyme used, palladium@iridium core-shell nanoparticles (Pd@Ir NPs), had ultrahigh enzyme-like activity, which was further explained by the electron transfer of Pd@Ir NPs and the change in the Gibbs free energy during catalysis through density functional theory calculations. With gastric cancer biomarkers pepsinogen I and pepsinogen II as model targets, this assay could achieve a cutoff value of 10 pg/mL, which was 200-fold lower than that without signal enhancement. The assay was applied to correctly identify 8 positive and 28 negative clinical samples. Overall, this BN-ISCRD-based LFIA showed great merits and potential in the application of ultrasensitive disease diagnosis.

Tumor-derived extracellular vesicles (T-EVs) hold great promise for understanding cancer biology and improving cancer diagnostics and therapeutics. Herein, we developed multivalent DNA flowers (DFs) containing repeated and equidistant EpCAM aptamers for the efficient isolation of T-EVs. The multivalent aptamer chains in DFs had good flexibility to adapt to the surface morphology of T-EVs and achieved multivalent ligand-receptor interactions, thus showing enhanced isolation ability compared to monovalent aptamers. Compared with other materials for isolation of EVs, DFs were generated by rolling circle amplification (RCA) and self-assembled into microspheres in a one-pot reaction, and the recognition molecules (aptamers) were directly replicated and assembled during the RCA reaction instead of chemical modification and immobilization on the surface of solid materials. Moreover, as optically transparent biomaterials, the content of EpCAM + EVs could be directly reflected via membrane-based hydrophobic assembly of signaling modules in DFs@EpCAM + EVs complex, and we found that the amount of EpCAM + EVs showed greater accuracy in cancer diagnosis than total EVs (88.3 vs 69.7%) and was also higher than the clinically commonly used marker carcinoembryonic antigen (CEA) (88.3 vs 76.7%). In addition, T-EVs could be released by lysis of DFs with the nuclease, gently and easily, keeping high intact and activity of EVs for downstream biological function studies. These results demonstrated that DFs are efficient and nondestructive tools for isolation, detection, and release of T-EVs.

Glycoproteins produced and secreted from specific cells and tissues are associated with several diseases and emerge as typical biomarkers to provide useful information in cancer diagnosis considering their abnormal expression levels. In this work, we design a universal method to achieve the accurate and sensitive analysis of tumor-associated glycoprotein biomarkers based on both carbohydrate recognition and protein recognition at the same protein surface. The byproduct of dual recognition-induced proximity amplification, pyrophosphate, triggers the disassembly of methylene blue-encapsulated metal-organic frameworks, MB@ZIF-90. As a result, methylene blue molecules are released to arouse amplified electrochemical responses for glycoprotein analysis. Experimental results demonstrate the high-accuracy analysis of carcinoembryonic antigen, a typical glycoprotein biomarker in cancer diagnosis, in a linear range of 0.001-100 ng mL -1 with a low limit of detection of 0.419 pg mL -1 . The method also displays satisfactory specificity and recoveries in complex serum samples and proves good versatility by adopting two other tumor-associated glycoprotein biomarkers, α-fetoprotein and mucin-1, as the targets. Therefore, this work provides a valuable tool for the analysis of glycoprotein biomarkers, which may be of great potential in early warning of malignant tumors in clinical applications.

Optical imaging has become an indispensable technology in the clinic. The molecular design of cell-targeted and highly sensitive materials, the validation of specific disease biomarkers, and the rapid growth of clinically compatible instrumentation have altogether revolutionized the way we use optical imaging in clinical settings. One prime example is the application of cancer-targeted molecular imaging agents in both trials and routine clinical use to define the margins of tumors and to detect lesions that are "invisible" to the surgeons, leading to improved resection of malignant tissues without compromising viable structures. In this Perspective, we summarize some of the key research advances in chemistry, biology, and engineering that have accelerated the translation of optical imaging technologies for use in human patients. Finally, our paper comments on several research areas where further work will likely render the next generation of technologies for translational optical imaging.

Nucleic acid modifications include a wide range of epigenetic and epitranscriptomic factors and impact a wide range of nucleic acids due to their profound influence on biological inheritance, growth, and metabolism. The recently developed methods of mapping and characterizing these modifications have promoted their discovery as well as large-scale studies in eukaryotes, especially in humans. Because of these pioneering strategies, nucleic acid modifications have been shown to have a great impact on human disorders such as cancer. Therefore, whether nucleic acid modifications could become a new type of biomarker remains an open question. In this review, we briefly look back at classical nucleic acid modifications and then focus on the progress made in investigating these modifications as diagnostic biomarkers in clinical therapy and present our perspective on their development prospects.

Tremendous progress in nanotechnology and nanomedicine has made a significant positive effect on cancer treatment by integrating multicomponents into a single multifunctional nanosized delivery system for combinatorial therapies. Although numerous nanocarriers developed so far have achieved excellent therapeutic performance in mouse models via elegant integration of chemotherapy, photothermal therapy, photodynamic therapy, sonodynamic therapy, and immunotherapy, their synthetic origin may still cause systemic toxicity, immunogenicity, and preferential detection or elimination by the immune system. Exosomes, endogenous nanosized particles secreted by multiple biological cells, could be absorbed by recipient cells to facilitate intercellular communication and content delivery. Therefore, exosomes have emerged as novel cargo delivery tools and attracted considerable attention for cancer diagnosis and treatment due to their innate stability, biological compatibility, and biomembrane penetration capacity. Exosome-related properties and functions have been well-documented; however, there are few reviews, to our knowledge, with a focus on the combination of exosomes and nanotechnology for the development of exosome-based theranostic platforms. To make a timely review on this hot subject of research, we summarize the basic information, isolation and functionalization methodologies, diagnostic and therapeutic potential of exosomes in various cancers with an emphasis on the description of exosome-related nanomedicine for cancer theranostics. The existing appealing challenges and outlook in exosome clinical translation are finally introduced. Advanced biotechnology and nanotechnology will definitely not only promote the integration of intrinsic advantages of natural nanosized exosomes with traditional synthetic nanomaterials for modulated precise cancer treatment but also contribute to the clinical translations of exosome-based nanomedicine as theranostic nanoplatforms.

Cell heterogeneity poses a formidable challenge for tumor theranostics, requiring high-resolution strategies for intercellular bioanalysis between single cells. Nanoelectrode-based electrochemical analysis has attracted much attention due to its advantages of label-free characteristics, relatively low cost, and ultra-high resolution for single-cell analysis. Here, we have designed and developed a subcellular biolabeling and bioresponsive real-time monitoring strategy for precise bioimaging-guided cancer diagnosis and theranostics. Our observations revealed the apparent intracellular migration of biosynthetic Au nanoclusters (Au NCs) at different subcellular locations, i.e., from the mitochondria to the mitochondrion-free region in the cytoplasm, which may be helpful for controlling over the biosynthesis of Au NCs. Considering the precise biolabeling advantage of the intracellular biosynthetic Au NCs for biomedical imaging of cancers, it is important to realize the biosynthetic Au NC-enabled precise control in real-time theranostics of cancer cells. Therefore, this work raises the possibility to achieve subcellular monitoring of H 2 O 2 for targeting cancer theranostics, thereby providing a new way to explore the underlying mechanism and imaging-guided tumor theranostics.

In this work, an ingenious sensor technology was established by integrating the EBFCs on a flexible paper strip carrier (PE) that was used for simultaneous detection of tumor markers in complex samples. Adopting high performance ultrathin graphdiyne (U-GDY) as the substrate can increase the enzyme load, accelerate the electron transfer rate, and significantly enhance the detection sensitivity. A homologous DNA nanomanager strategy cleverly uses signal switches to recycle and amplify target miRNAs, while the smartphone receives real-time instantaneous current values to realize multivariate detection. Electrochemical data show that the detection limits (LODs) of miRNA-21 and miRNA-155 are 0.09 and 0.15 fM in the wide concentration range. The results confirm that the tailored sensor platform provides a strategy for the early cancer diagnosis and lays the foundation for the construction of a flexible wearable platform.

Accurate identification of tumor margins during cancer surgeries relies on a rapid detection technique that can perform high-throughput detection of multiple suspected tumor lesions at the same time. Unfortunately, the conventional histopathological analysis of frozen tissue sections, which is considered the gold standard, often demonstrates considerable variability, especially in many regions without adequate access to trained pathologists. Therefore, there is a clinical need for a multitumor-suitable complementary tool that can accurately and high-throughput assess tumor margins in every direction within the surgically resected tissue. We herein describe a high-throughput three-dimensional (3D) histological electrophoresis device that uses tumor-specific proteins to identify and contour tumor margins intraoperatively. Testing on seven cell-line xenograft models and human cervical cancer models (representing five types of tissues) demonstrated the high-throughput detection utility of this approach. We anticipate that the 3D histological electrophoresis device will improve the accuracy and efficiency of diagnosing a wide range of cancers.

Surface-enhanced Raman spectroscopy (SERS) with ultrasensitive vibrational fingerprints enables quick identification and trace detection of various kinds of molecules. But proteins usually have low Raman cross sections and are difficult to generate recognizable signals in direct SERS detection. Recently, nucleic acid-peptide conjugates are emerging with great potential in structuring, assembling, catalyzing, sensing, etc., and the coupling of aptamers further enables superior biological recognition and programmability. Here, we develop the aptamer-peptide conjugates as a new kind of SERS probe for direct high-specific profiling abnormal protein levels in cancer patients. The aptamer conjugated with glutathione (GSH) functions as both the recognition element and the SERS reporters that can simultaneously generate SERS fingerprints of both peptides and nucleic acids. This kind of biocompatible probe appears to have excellent performance in high-salt environments and realizes rapid, simple, and multisignal detection of thrombin (TB). Data-driven soft independent modeling of class analogy (DD-SIMCA) is used to distinguish SERS profiles of actual blood samples and realize the identification and classification of cancer patients. Furthermore, the effect of low-temperature storage time on blood samples is analyzed by tracking the changes of SERS profiles; the results hint that plasma samples stored under 4 °C for more than 2 days could generate false negative results due to TB hydrolysis, which has important implications for clinical sample analysis. This kind of nucleic acid-peptide conjugate provides new ideas for SERS sensing strategy in the future.

Recent advances in high-resolution biomedical imaging have improved cancer diagnosis, focusing on morphological, electrical, and biochemical properties of cells and tissues, scaling from cell clusters down to the molecular level. Multiscale imaging revealed high complexity that requires advanced data processing methods of multifractal analysis. We performed label-free multiscale imaging of surface potential variations in human ovarian cancer cells using Kelvin probe force microscopy (KPFM). An improvement in the differentiation between nonmalignant and cancerous cells by multifractal analysis using adaptive versus median threshold for image binarization was demonstrated. The results reveal the multifractality of cancer cells as a new biomarker for cancer diagnosis.

Cell membrane proteins play a crucial role in the development of early cancer diagnosis strategies and precision medicine techniques. However, the application of aptamers in cell membrane protein-based biomedical research is limited by their inherent drawbacks, such as sensitivity to the recognition environment and susceptibility to enzymatic degradation, which leads to the loss of recognition ability. To address these challenges, this study presents a subzero-temperature-enabled molecule stacking strategy for the on-demand tailoring of aptamer glues for the precision recognition and efficient degradation of membrane protein. Mechanistic studies revealed that nucleic acid molecule stacking occurred during the freezing and melting processes, facilitating a rapid click reaction by bringing two reactive groups together. In vitro investigations demonstrated that the strategy confers aptamer glues with significantly enhanced specific recognition ability and binding affinity, allowing the distinction of a targeted cell line from a nontargeted cell line. Moreover, the engineered aptamer glue exhibited impressive targeted cell membrane protein degradation ability; around 74% of the c-Met protein was degraded in 24 h. These findings hold great potential for advancing cancer diagnosis and targeted therapy through the development of more stable and reliable aptamer probes.

Circular RNAs (circRNAs) as endogenous non-coding RNAs are characterized by covalently closed circular structures, and they widely exist in mammalian cells. The aberrant expression of circRNAs may result in various diseases. Herein, we demonstrate the construction of genetically encoded light-up RNA aptamers for ultrasensitive and label-free detection of circRNA mitochondrial tRNA translation optimization 1 (circMTO1) in cancer cells and tissues. The light-up RNA aptamers are generated by proximity ligation-activated recombinase polymerase amplification (RPA)-assisted transcription amplification. When circMTO1 is present, it initiates the proximity ligation reaction, activating RPA to produce numerous long double-stranded DNAs containing T7 promoters. Subsequently, the RPA products are identified by T7 RNA polymerase, initiating the transcription amplification reaction to generate abundant Spinach RNA aptamers. Spinach RNA aptamers can bind with DFHBI (3,5-difluoro-4-hydroxybenzylidene imidazolidinone) dye to produce a distinct fluorescence signal with near-zero background. This biosensor exhibits excellent selectivity and high sensitivity with a limit of detection of 2.54 aM. It can accurately monitor cellular circMTO1 at the single-cell level and discriminate the expression of circMTO1 between breast cancer patient tissues and healthy tissues. Notably, this biosensor can be employed to measure other nucleic acids by altering the corresponding target recognition sequences, providing a valuable platform for cancer diagnosis and biomedical study.

Chemiluminescence (CL) with intensive emission has been pursued for decades. It is still challenging to find a new mechanism to enhance CL. In this work, confinement-enhanced CL was developed for the first time by the coembedding of N-(aminobutyl)-N-(ethylisoluminol) (ABEI) and Co 2+ into gold nanoparticle-modified covalent-organic frameworks (COFs). For the consideration of improving the hydrophilicity of COFs and facilitating subsequent biological modification, gold nanoparticles were first reduced on the COF surface (Au-COF) in situ without other reducing reagents. By virtue of the abundant imine bond and π backbones, ABEI and Co 2+ were embedded in Au-COF synergistically through π-π stacking and coordination. The confinement of ABEI and Co 2+ into Au-COF brought an over 20-fold enhancement of CL intensity compared to that of adding them to a liquid phase, which benefitted from the three aspects of the confinement effect, including the molecular enrichment effect, the physical constraint effect, and the molecular preorganization effect. As proof of concept, a lipid-protein dual-recognition sandwich strategy based on this CL-functionalized COF was developed for the detection of breast cancer cell line-derived extracellular vesicles (EVs) with four orders of magnitude improvement in the detection limit compared to ELISA. The successful distinction of human epidermal growth factor receptor 2 (HER2)-positive patients from HER2-negative patients indicated the great application potential of the proposed bioassay in HER2-positive breast cancer diagnosis. This work proposed a novel enhancement mechanism for CL based on crystalline porous materials, which provides a new perspective for the development of CL-functionalized materials for biosensors and bioassays.

The in situ detection of low-content cancer biomarkers by an endogenous activator instead of an exogenous initiator in vitro remains a great challenge, leaving a gap in the development of a tumor-specific nanosensor with an endogenous protease-activatable manner. Herein, we proposed an endogenous protease-activatable nanosensor (PA-NS) guided by peptide nucleic acid-peptide-DNA copolymers to realize AND-gated and dual-model sensing of miRNA-21 (miR-21) by combining electrochemical detection with optical imaging in living tumor cells, without an additional introduction of an exogenous activator or nanomaterials. Moreover, the PA-NS can only be activated by "dual keys" (overexpressed miR-21 and cathepsin B protease in tumor cells) simultaneously, which enables effective improvement of the tumor-to-healthy cells ratio. The fluorescence intensity measured in single tumor cells was ∼3.5-fold higher than that in single healthy cells, and the electrochemical response decreased ∼30% in the presence of target miRNA. Furthermore, studies on regulation of the protease activity and miR-21 fluctuation under external stimulation have contributed to our understanding of the biological processes and drug screenings underlying disease development. This specific endogenous protease-mediated manner for dual-model detection of miRNA guarantees excellent tumor-selective capability, which offers new opportunities to study cell heterogeneity and provides more reliable fundamentals for the diagnosis and treatment of cancer down to the single-cell level.

Wearable, point-of-care diagnostics, and biosensors are on the verge of bringing transformative changes in detection, management, and treatment of cancer. Bioinspired materials with new forms and functions have frequently been used, in both translational and commercial spaces, to fabricate such diagnostic platforms. Engineered from organic or inorganic molecules, bioinspired systems are naturally equipped with biorecognition and stimuli-sensitive properties. Mechanisms of action of bioinspired materials are deeply connected with thermodynamically or kinetically controlled self-assembly at the molecular and supramolecular levels. Thus, integration of bioinspired materials into wearable devices, either as triggers or sensors, brings about unique device properties usable for detection, capture, or rapid readout for an analyte of interest. In this review, we present the basic principles and mechanisms of action of diagnostic devices engineered from bioinspired materials, describe current advances, and discuss future trends of the field, particularly in the context of cancer.

Single-stranded DNA (ssDNA) allows flexible and directional modifications for multiple biological applications, while being greatly limited by their poor stability, increased folding errors, and complicated sequence optimizations. This greatly challenges the design and optimization of ssDNA sequences to fold stable 3D structures for diversified bioapplications. Herein, the stable pentahedral ssDNA framework nanorobots (ssDNA nanorobots) were intelligently designed, assisted by examining dynamic folding of ssDNA in self-assemblies via all-atom molecular dynamics simulations. Assisted by two functional siRNAs (S1 and S2), two ssDNA strands were successfully assembled into ssDNA nanorobots, which include five functional modules (skeleton fixation, logical dual recognition of tumor cell membrane proteins, enzyme loading, dual-miRNA detection and synergy siRNA loading) for multiple applications. By both theoretical calculations and experiments, ssDNA nanorobots were demonstrated to be stable, flexible, highly utilized with low folding errors. Thereafter, ssDNA nanorobots were successfully applied to logical dual-recognition targeting, efficient and cancer-selective internalization, visual dual-detection of miRNAs, selective siRNA delivery and synergistic gene silencing. This work has provided a computational pathway for constructing flexible and multifunctional ssDNA frameworks, enlarging biological application of nucleic acid nanostructures.