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Iron, nitrogen-co-doped carbon quantum dots (Fe,N-CDs) were prepared via a simple one-step hydrothermal method. The quantum yield of fluorescence reached about 27.6% and the blue-emissive Fe,N-CDs had a mean size of 3.76 nm. The as-prepared carbon quantum dots showed good solubility, a high quantum yield, good biocompatibility, low cytotoxicity, and high photostability. Interestingly, the as-prepared Fe,N-CDs exhibited good selectivity and sensitivity toward both hematin and ferric ions, and the limit of detection for hematin and ferric ions was calculated to be about 0.024 μM and 0.64 μM, respectively. At the same time, Fe,N-CDs were used for imaging HeLa cells and showed that most Fe,N-CDs were detained in the lysosome. Thus, this fluorescent probe has potential application in the quantitative detection of hematin or Fe3+ in a complex environment and for determining Fe3+ at the cellular level.

Immunomagnetic micro/nanoparticles (IMNs) have been widely used to isolate rare circulating tumor cells (CTCs) from blood samples for early diagnosis of cancers. However, when entering into biofluids, IMNs nonspecifically adsorb biomolecules and the in situ formed biomolecule corona covers IMN surface ligands and weakens the targeting capabilities of IMNs. In this work, we demonstrated that by surface coating of IMNs with red blood cell (RBC)-derived vesicles, the obtained biomimetic particles (RBC-IMNs) basically adsorb no biomolecules and maintain the CTC targeting ability when exposed to plasma. Compared to IMNs, RBC-IMNs exhibited an excellent cell isolation efficiency in spiked blood samples, which was improved to 95.71% from 60.22%. Furthermore, by using RBC-IMNs, we successfully isolated CTCs in 28 out of 30 prostate cancer patient blood samples and further showed the robustness of RBC-IMNs in downstream cell sequencing. The work presented here provides a new insight into developing targeted nanomaterials for biological and medical applications.

Although anti-PD-1 immunotherapy is widely used to treat melanoma, its efficacy still has to be improved. In this work, we present a therapeutic method that combines immunotherapy and starvation therapy to achieve better antitumor efficacy. We designed the CMSN-GOx method, in which mesoporous silica nanoparticles (MSN) are loaded with glucose oxidase (GOx) and then encapsulate the surfaces of cancer cell membranes to realize starvation therapy. By functionalizing the MSN's biomimetic surfaces, we can synthesize nanoparticles that can escape the host immune system and homologous target. These attributes enable the nanoparticles to have improved cancer targeting ability and enrichment in tumor tissues. Our synthetic CMSN-GOx complex can ablate tumors and induce dendritic cell maturity to stimulate an antitumor immune response. We performed an in vivo analysis of these nanoparticles and determined that our combined therapy CMSN-GOx plus PD-1 exhibits a better antitumor therapeutic effect than therapies using CMSN-GOx or PD-1 alone. Additionally, we used the positron emission tomography imaging to measuring the level of glucose metabolism in tumor tissues, for which we investigate the effect with the cancer therapy in vivo.

Carbon nanodots (CDs) are novel forms of zero-dimensional carbonaceous nanomaterials, which have attracted the attention of researchers. Long wavelength emission decreases the interference of auto-fluorescence of tissue and can also penetrate more deeply. However, it is still a challenge to develop red emissive CDs. In this work, nitrogen, sulfur co-doped CDs are synthesized with red light emission through one-step solvothermal treatment. The as-synthesized CDs exhibit excellent properties such as high chemical stability, good biocompatibility, excellent photoluminescence properties, good water solubility, and low toxicity, and also show high sensitivity and selectivity towards Fe

Carbon dots (CDs) have received much attention in constructing metal-free phosphorescence materials, but it is still a huge challenge to develop a material with long lifetime and phosphorescence emission in aqueous environments. In this work, we designed and synthesized a universal approach to produce N-doped carbon dots (N-CDs) with efficient room-temperature phosphorescence (RTP) through simple heating treatment. Then, we prepared a kind of highly efficient N-CDs/MA nanocomposite phosphorescence materials by synthesized through N-CDs mixed with melamine. Excitingly, the characterizations indicate that the nanocomposite materials not only have an ultralong phosphorescence lifetime in the solid state, but also exhibit blue-green RTP in aqueous medium. In addition, based on their unusual RTP features, the obtained RTP materials can be successfully applied in ion determination and shows great potentials in the fields of anti-counterfeiting and information encryption.

In recent years, carbon dot (CD)-based fluorescent sensors for selective ions or small biomolecules have drawn great attention. In this work, highly fluorescent CDs (QY = 21%) were prepared from 2,3-diamino pyridine as the precursor through a facile solvothermal process. The CDs showed high stability and a green emission in aqueous, and the optimal emission wavelength of CDs is 508 nm under the excitation wavelength of 438 nm. Interestingly, a CDs-based nanoprobe was developed for a selective and sensitive fluorescence quenching response to NO2− in water, and the quenching mechanism was investigated in the work. Besides, the recovery rates of NO2− in the range of 98–103.5% were found to be acceptable, indicating that the proposed CDs could be act as potential candidates for determination of nitrite ions in real samples. Meanwhile, the nanoprobe was also successfully employed in a visualization biosensing platform for determination of NO2− in living cells due to its eminent biocompatibility.

Assessment of microbial viability plays a key role in human health protection. Optical imaging based on fluorescent dyes is a simple and convenient way to assess microbial viability. However, it is still a challenge to obtain stable, nontoxic and low-cost dyes. Herein, we prepared a nitrogen and phosphorus co-doped carbon nanodots (N, P-CDs) via a one-step solvothermal method. The prepared CDs possess plenty of functional groups and exhibit high stability, good biocompatibility, excellent photoluminescent and low toxicity. Especially, the properties of high quantum yield (89.9%) and highly negative surface charge (−41.9 mV) make the prepared N, P-CDs ideal materials for microbial differentiation. Compared with commercial dyes, our CDs are more stable, cost less, which can rapidly distinguish dead microorganisms from living ones with higher specificity.

A new cyanide probe has been prepared by one-step synthesis and evaluated by UV–vis and fluorescent method. This probe is combined by a fluorene part and a hemicyanine group through a conjugated linker, which is found to show rapid response, high selectivity and sensitivity for cyanide anions with significant dual colorimetric and fluorescent signal changes in aqueous solution. An intramolecular charge transfer (ICT) effect plays a key role in the CN− sensing properties, and the details of this mechanism are further supported by DFT and TD-DFT calculations. The theoretical study shows that the introduction of CN- twists the original plane structure and blocks the ICT process in the whole molecule, which brings about the absorption blue-shift and the fluorescence quenching.

Carbon nanodots (CDs) are novel forms of zero-dimensional carbonaceous nanomaterials, which have attracted the attention of researchers. Long wavelength emission decreases the interference of auto-fluorescence of tissue and can also penetrate more deeply. However, it is still a challenge to develop red emissive CDs. In this work, nitrogen, sulfur co-doped CDs are synthesized with red light emission through one-step solvothermal treatment. The as-synthesized CDs exhibit excellent properties such as high chemical stability, good biocompatibility, excellent photoluminescence properties, good water solubility, and low toxicity, and also show high sensitivity and selectivity towards Fe3+ sensing. The detection limit is as low as 17.3 nM. In addition, the CDs are successfully utilized for monitoring Fe3+ in living cells, which demonstrates their promising applicability in bioimaging. Furthermore, a test paper based on the CQDs has been prepared. This developed nanosensor can detect Fe3+ visually and sensitively without any further steps which will make a great contribution to the development of ion sensors.

As an important bioactive component in plants, chlorogenic acid (CGA) has been widely studied for its potential role in human health. In this work, cyan fluorescent silicon quantum dots were successfully synthesized via a simple one-pot method for the rapid detection of CGA. The optimal excitation and emission wavelength of the obtained SiQDs was 350 nm and 470 nm, respectively. When the CGA was added, the maximum emission intensity of the SiQDs can be effectively quenched due to dynamic and static mixed quenching mechanisms. More significantly, there was a remarkable linear correlation between fluorescence quenching efficiency and a broad concentration of CGA solution range from 10 to 150 μmol/L with a limit of detection (LOD) of 0.43 μmol/L. Furthermore, the proposed SiQDs were successfully applied to analyze CGA in coffee beans and instant coffee after simple pretreatment with satisfactory results. Based on these, a high sensitivity and excellent selectivity fluorescent probe detection system was constructed, and it provides a valuable platform for the detection of CGA and has broad application prospects in the biological and pharmaceutical analysis field.

It is well known that the calcium ion is essential for maintaining life activities in living organisms, and it is of great significance to detect the intracellular calcium concentration. For the detection of calcium ions, we developed a new type of fluorescent carbon dots (CDs), whose surface was modified by ethylenebis(oxyethylenenitrilo)tetraacetic acid (EGTA) through a secondary hydrothermal method. This is a simple and convenient chemical preparation method because all reactions are carried out in the same autoclave, and the final product is directly the EGTA-modified CDs. The CDs exhibit bright blue fluorescence, and as the calcium concentration increases, the fluorescence intensity drops sharply. The fluorescence quenching correlates with the concentration of calcium ions and has a good linearity in the range of 15-300 μM with a detection limit of 0.38 μM. The experimental results confirmed that the detection of calcium ions by CDs is a static fluorescence quenching process. Also, cytotoxicity test and cellular imaging experiments have shown that the CDs are nontoxic and biocompatible.

Capturing circulating tumor cells (CTCs) from peripheral blood for subsequent analyses has shown potential in precision medicine for cancer patients. Broad as the prospect is, there are still some challenges that hamper its clinical applications. One of the challenges is to maintain the viability of the captured cells during the capturing and releasing processes. Herein, we have described a composite material that could encapsulate a magnetic Fe3O4 core in a MIL-100 shell (MMs), which could respond to pH changes and modify the anti-EpCAM antibody (anti-EpCAM-MMs) on the surface of MIL-100. After the anti-EpCAM-MMs captured the cells, there was no need for additional conditions but with the acidic environment during the cell culture process, MIL-100 could realize automatic degradation, leading to cell self-release. This self-release model could not only improve the cell viability, but could also reduce the steps of the release process and save human and material resources simultaneously. In addition, we combined clinical patients' case diagnosis with the DNA sequencing and next generation of RNA sequencing technologies in the hope of precision medicine for patients in the future.

Filtration of circulating tumor cells (CTCs) in peripheral blood is of proven importance for early cancer diagnosis, treatment monitoring, metastasis diagnosis, and prognostic evaluation. However, currently available strategies for enriching CTCs, such as magnetic activated cell sorting (MACS), face serious problems with purity due to nonspecific interactions between beads and leukocytes in the process of capturing. In the present study, the tumor-targeting molecule folic acid (FA) and magnetic nanoparticles (MNPs) were coated on the surface of red blood cells (RBCs) by hydrophobic interaction and chemical conjugation, respectively. The resulting engineered RBCs rapidly adhered to CTCs and the obtained CTC-RBC conjugates were isolated in a magnetic field. After treatment with RBC lysis buffer and centrifugation, CTCs were released and captured. The duration of the entire process was less than three hours. Cell counting showed that the capture efficiency was above 90% and the purity of the obtained CTCs was higher than 75%. The performance of the proposed method exceeded that of MACS® beads (80% for capture efficiency and 20% for purity) under the same conditions. The obtained CTCs could be successfully re-cultured and proliferated in vitro. Our engineered RBCs have provided a novel method for enriching rare cells in the physiological environment.

Recently, red blood cell (RBC) membrane-coated nanoparticles have attracted much attention because of their excellent immune escapability; meanwhile, gold nanocages (AuNs) have been extensively used for cancer therapy due to their photothermal effect and drug delivery capability. The combination of the RBC membrane coating and AuNs may provide an effective approach for targeted cancer therapy. However, few reports have shown the utilization of combining these two technologies. Here, we design erythrocyte membrane-coated gold nanocages for targeted photothermal and chemical cancer therapy. First, anti-EpCam antibodies were used to modify the RBC membranes to target 4T1 cancer cells. Second, the antitumor drug paclitaxel (PTX) was encapsulated into AuNs. Then, the AuNs were coated with the modified RBC membranes. These new nanoparticles were termed EpCam-RPAuNs. We characterized the capability of the EpCam-RPAuNs for selective tumor targeting via exposure to near-infrared irradiation. The experimental results demonstrate that EpCam-RPAuNs can effectively generate hyperthermia and precisely deliver the antitumor drug PTX to targeted cells. We also validated the biocompatibility of the EpCam-RAuNs in vitro. By combining the molecularly modified targeting RBC membrane and AuNs, our approach provides a new way to design biomimetic nanoparticles to enhance the surface functionality of nanoparticles. We believe that EpCam-RPAuNs can be potentially applied for cancer diagnoses and therapies.

Nanotechnology possesses the potential to revolutionize the diagnosis and treatment of tumors. The ideal nanoparticles used for in vivo cancer therapy should have long blood circulation times and active cancer targeting. Additionally, they should be harmless and invisible to the immune system. Here, we developed a biomimetic nanoplatform with the above properties for cancer therapy. Macrophage membranes were reconstructed into vesicles and then coated onto magnetic iron oxide nanoparticles (Fe3O4 NPs). Inherited from the Fe3O4 core and the macrophage membrane shell, the resulting Fe3O4@MM NPs exhibited good biocompatibility, immune evasion, cancer targeting and light-to-heat conversion capabilities. Due to the favorable in vitro and in vivo properties, biomimetic Fe3O4@MM NPs were further used for highly effective photothermal therapy of breast cancer in nude mice. Surface modification of synthetic nanomaterials with biomimetic cell membranes exemplifies a novel strategy for designing an ideal nanoplatform for translational medicine.

The development of probes for rapid and selective detection of peroxynitrite in vivo is of great importance in biological science. We investigate different photoinduced electron transfer (PIET) processes of two generations of peroxynitrite probes. Each has fluorescein and phenol moieties; one is conjugated by an ether linkage while the other is conjugated via an amine linkage. Using theoretical calculations, we demonstrated that the PIET in the probe with an ether linkage occurs from the benzoic acid to the xanthene moiety. In contrast, the PIET in the probe with an amine linkage occurs from the phenol moiety to the fluorescein. This suggests that better sensitivity can be accomplished in probes with an amine linkage than with an ether linkage. Following this model, we designed two novel peroxynitrite probes and simulated their detection capabilities in the near-infrared region.

Responsive cross-linked block copolymer micelles which have emerged as promising drug delivery systems showed high stability and on-demand drug release. The combination therapy of cancer can be achieved via co-delivery of varying therapeutic molecules in one system. Here, we developed a redox-responsive core cross-linked (CCL) micelle conjugated with cypate and cisplatin prodrugs within the cores for synergistic photothermal and chemotherapy. The block copolymer, poly[(2-(2-methoxyethoxy)ethyl methacrylate)-co-(N-methacryloxy succinimide)]-block-poly(N-(2-hydroxypropyl) methacrylamide) (P(MEO2MA-co-MASI)-b-PHPMA), was synthesized via reversible addition–fragment chain transfer (RAFT) polymerization. After partial amidation reaction of succinimide with 3-azidopropylamine, the alkynyl-functionalized cypate and Pt(IV) complex were conjugated via click reaction. The CCL micelles were fabricated by core cross-linking at 37 °C in aqueous solution using cystamine as the cross-linker. P(Pt-Cy-MEO2MA)-b-PHPMA CCL micelles showed redox-responsive cross-linker cleavage and cisplatin drug release in the presence of reductants. The conjugated cypate moieties in the cores of CCL micelles resulted in photothermal temperature increase and reactive oxygen species (ROS) generation under 805 nm near infrared (NIR) laser irradiation. The cytotoxicity of CCL micelles was investigated with and without NIR irradiation. A significant synergistic effect of photothermal therapy and chemotherapy was demonstrated against cisplatin-resistant human lung cancer cells A549R under NIR irradiation.

In this letter, we demonstrate an uncooled, sensitivity-enhanced infrared (IR) detector based on a Lamb wave sensor coated with polydopamine (PDA). The real-time resonant frequency responses of the sensors with and without PDA coating were measured as functions of IR intensity. Compared to the traditional Lamb wave sensor, the PDA-coated Lamb sensor exhibits a highly linear relationship between resonance frequency and IR intensity, and the slope representing the sensitivity of IR detection is nearly one order of magnitude higher. The enhanced sensitivity is mainly attributed to the optical-thermal transition of PDA nanoparticles rather than the modulation of the thermal-acoustic effect. This mechanism for achieving highly sensitive uncooled IR detectors holds great promise for application in photo-thermal therapy along with other military and civilian fields.

Near-infrared (NIR) light-triggered drug release systems are promising for drug delivery applications in view of the advantages of NIR light, which include high tissue penetration and low damage. In this report, we developed nanogels (NGs) by supramolecular self-assembly from adamantine (AD)-conjugated copolymer, poly[poly(ethylene glycol)monomethyl ether metharcylate]-co-poly(N-(2-hydroxypropyl)methacrylamide)-co-poly(N-adamantan-1-yl-2-methacrylamide) (PPEGMA-co-PHPMA-co-PADMA), and β-cyclodextrin (β-CD)-functionalized poly(amidoamine) (PAMAM) dendrimer based on the host–guest interaction of the AD and β-CD moieties, and they were used to encapsulate indocyanine green (ICG) and doxorubicin (DOX) for combined photothermal-chemotherapy. NGs simultaneously loading ICG and DOX (DINGs) showed significant photothermal effects and stimuli-triggered drug release under NIR laser irradiation by the photothermal-induced relaxation or dissociation of the NGs. In vitro cytotoxicity evaluation of DINGs under NIR irradiation demonstrated the synergistic effects of hyperthermia, photothermal-triggered drug release, and chemotherapy. In vivo investigation revealed their high accumulation in tumor tissue and significant tumor growth suppression under NIR irradiation. These NIR light-triggered drug release NGs represent efficient and promising anticancer drug vectors for the combined photothermal-chemotherapy of cancer to maximize therapeutic efficacy and minimize side effects.