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Green and recyclable ternary deep eutectic solvent was developed to selectively extract lignin of high purity, desirable molecular weight and monomeric yield for applications in reinforcement materials and bio-oil was produced from biomass.

The rapid, accurate and highly sensitive detection of NH4+ under non-alkaline conditions is achieved by electrooxidizing NH4+ to hydrazine via H2O2 derived from the oxygen reduction reaction over a self-supporting Ag/Fe2O3/TiO2 sensor.

Bioinformatics and machine learning tools have made it possible to integrate data across different -omics platforms for novel multiomic insights into diseases. To synergistically process -omics data in an integrative manner, analyte extractions for each -omics type need to be done on the same set of clinical samples. Therefore, we introduce a simultaneous dual extraction method for generating both metabolomic (polar metabolites only) and glycomic (protein-derived N-glycans only) profiles from one sample with good extraction efficiency and reproducibility. As proof of the usefulness of the extraction and joint-omics workflow, we applied it on platelet samples obtained from a cohort study comprising 66 coronary heart disease (CHD) patients and 34 matched healthy community-dwelling controls. The metabolomics and N-glycomics data sets were subjected to block partial least-squares-discriminant analysis (block-PLS-DA) based on sparse generalized canonical correlation analysis (CCA) for identifying relevant mechanistic interactions between metabolites and glycans. This joint-omics investigation revealed intermodulative roles that protein-bound carbohydrates or glycoproteins and amino acids have in metabolic pathways and through intermediate protein dysregulations. It also suggested a protective role of the glyco-redox network in CHD, demonstrating proof-of-principle for a joint-omics analysis in providing new insights into disease mechanisms, as enabled by a simultaneous polar metabolite and protein-derived N-glycan extraction workflow.

Acute myocardial infarction (AMI) is a leading cause of mortality and morbidity worldwide. Diagnostic challenges remain in this highly time-sensitive condition. Using capillary electrophoresis-laser-induced fluorescence, we analyzed the blood plasma N-glycan profile in a cohort study comprising 103 patients with AMI and 69 controls. Subsequently, the data generated was subjected to classification modeling to identify potential AMI biomarkers. An area under the Receiving Operating Characteristic curve (AUCROC) of 0.81 was obtained when discriminating AMI vs. non-MI patients. We postulate that the glycan profile involves a switch from a pro- to an anti-inflammatory state in the AMI pathophysiology. This was supported by significantly decreased levels in galactosylation, alongside increased levels in sialylation, afucosylation and GlcNAc bisection levels in the blood plasma of AMI patients. By substantiating the glycomics analysis with immunoglobulin G (IgG) protein measurements, robustness of the glycan-based classifiers was demonstrated. Changes in AMI-related IgG activities were also confirmed to be associated with alterations at the glycosylation level. Additionally, a glycan-biomarker panel derived from glycan features and current clinical biomarkers performed remarkably (AUCROC = 0.90, sensitivity = 0.579 at 5% false positive rate) when discriminating between patients with ST-segment elevation MI (n = 84) and non-ST-segment elevation MI (n = 19). Moreover, by applying the model trained using glycomics information, AMI and controls can still be discriminated at 1 and 6 months after baseline. Thus, glycomics biomarkers could potentially serve as a valuable complementary test to current diagnostic biomarkers. Additional research on their utility and associated biomechanisms via a large-scale study is recommended.

Rapid industrialization is accompanied by the deterioration of the natural environment. The deepening crisis associated with the ecological environment has garnered widespread attention toward strengthening environmental monitoring and protection. Environmental sensors are one of the key technologies for environmental monitoring, ultimately enabling environmental protection. In recent decades, micro/nanomaterials have been widely studied and applied in environmental sensing owing to their unique dimensional properties. Electrospinning has been developed and adopted as a facile, quick, and effective technology to produce continuous micro- and nanofiber materials. The technology has advanced rapidly and become one of the hotspots in the field of nanomaterials research. Environmental sensors made from electrospun nanofibers possess many advantages, such as having a porous structure and high specific surface area, which effectively improve their performance in environmental sensing. Furthermore, by introducing functional nanomaterials (carbon nanotubes, metal oxides, conjugated polymers, etc.) into electrospun fibers, synergistic effects between different materials can be utilized to improve the catalytic activity and sensitivity of the sensors. In this review, we aimed to outline the progress of research over the past decade on electrospinning nanofibers with different morphologies and functional characteristics in environmental sensors.

In research enabling preclinical development and attaining a deeper understanding of the behavior of metallodrugs in cancer cells with acquired resistance, intracellular Pt accumulation could be considered an important biomarker and analytical focus. In this work, Pt accumulation patterns in terms of the number of cells and Pt mass in single cells were precisely defined by using inductively coupled plasma-mass spectrometry (ICP–MS) operating in a fast time-resolved analysis mode. This technique is otherwise known as single-cell (SC)–ICP–MS. By applying the nascent and validated SC–ICP–MS technique, comparisons across three Pt drugs (cisplatin, carboplatin, and oxaliplatin) in the A2780 and A2780cis ovarian cancer cell models could be made. Additional roles of transporters on top of passive diffusion and the drugs’ bioactivity could be postulated. The SC–ICP–MS-based observations also served as a cross-validation point to augment preexisting research findings on Pt-resistance mechanisms. Conjectures regarding S and Fe metabolism were also derived based on an additional and direct ICP–MS analysis of endogenous elements. Overall, our work not only confirms the utility of SC–ICP–MS in chemotherapeutic research, but also provided insights into further ICP–MS-based analytical capacities to be developed.

The capability of pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) for the direct analysis of endotoxins is demonstrated in this research article using the lipopolysaccharides of Pseudomonas aeruginosa 10. Analytical methods based on evolved gas analysis-MS, single-shot (SS) Py-GC-MS, and multishot heart cut Py-GC-MS were investigated. Among the various methods developed, the SS Py-GC-MS method shows superior potential for identifying bacterial endotoxins effectively through their biomarkers. The results obtained were validated with conventional mass spectral analysis after hydrolysis. The method was also evaluated for its robustness based on quality control criteria indicated by the U.S. EPA Method 8270D. When applied onto endotoxins of different Gram-negative bacteria, this method produced vastly distinct pyrograms. The results show that rapid and sensitive direct detection of endotoxins is possible with the Py-GC-MS method developed.

Acute myocardial infarction (AMI) is a leading cause of mortality and morbidity worldwide. Using a validated and efficient ICP-MS/MS-based workflow, a total of 30 metallomic features were profiled in a study comprising 101 AMI patients and 66 age-matched healthy controls. The metallomic features include 12 essential elements (Ca, Co, Cu, Fe, K, Mg, Mn, Na, P, S, Se, Zn), 8 non-essential/toxic elements (Al, As, Ba, Cd, Cr, Ni, Rb, Sr, U, V), and 10 clinically relevant element-pair product/ratios (Ca/Mg, Ca×P, Cu/Se, Cu/Zn, Fe/Cu, P/Mg, Na/K, Zn/Se). Preliminary linear regression with feature selection confirmed smoking status as a predominant determinant for the non-essential/toxic elements, and revealed potential routes of action. Univariate assessments with adjustments for covariates revealed insights into the ambivalent relationships of Cu, Fe, and P with AMI, while also confirming cardioprotective associations of Se. Also, beyond their roles as risk factors, Cu and Se may be involved in the response mechanism in AMI onset/intervention, as demonstrated via longitudinal data analysis with 2 additional time-points (1-/6-month follow-up). Finally, based on both univariate tests and multivariate classification modelling, potentially more sensitive markers measured as element-pair ratios were identified (e.g., Cu/Se, Fe/Cu). Overall, metallomics-based biomarkers may have utility for AMI prediction.

Persistent organic pollutants (POPs) accumulate in the organisms due to their hydrophobicity and resistance to xenobiotic metabolism. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is one of most representative POPs. Its pathophysiological effects have been extensively studied on many types of tissues but not on muscles. In this study, female C57BL/6J mouse model was used to analyze the long-term effects of maternal exposure to TCDD during gestation and lactation on the skeletal muscles (soleus, plantaris, and gastrocnemius) of the progeny during adulthood. The effects of re-exposure to TCDD in mice exposed during their development were also characterized. Female C57BL/6J mice were maternally exposed to TCDD or its vehicle (n-nonane in corn oil) and then re-exposed to TCDD or its vehicle at 9 weeks of age. The metabolites in the skeletal muscles were analyzed by gas chromatography–quadrupole time of flight-mass spectrometry (GC–qTOF-MS). Univariate analysis showed significant effects in certain metabolites in the skeletal muscle. It also showed that TCDD exerts a more significant impact on exposure to TCDD at 9 weeks of age than during maternal exposure for the soleus. On the other hand, TCDD exerts a more significant impact on mice maternally exposed to TCDD than at 9 weeks of age for the gastrocnemius. Multivariate analysis showed clear discrimination between the TCDD-exposed mice and the control. This study demonstrates the effects of TCDD observed following maternal exposure; some of them can be reinforced or attenuated by a re-exposure at the adult age, suggesting that the POP which mainly acts through the activation of the AhR leads to metabolic adaptation in the skeletal muscles. The period of exposure was a key factor in our study with TCDD playing a crucial role during the maternal period, as compared to when they were exposed at 9 weeks of age. It was inferred that disruption in amino acid metabolism might lead to a loss in muscle mass which may result in muscular atrophy. Our results also show that the metabolite profiles after perinatal exposure are different in different types of muscles even though they are all classified as skeletal muscles. Therefore, TCDD may affect the organism (specifically different skeletal muscles) in a non-homogenous manner.

Heavy metal (HM) pollution is a major global concern. Carbon dots (CDs) have demonstrated unique properties as sensing platforms for HMs detection. This review summarizes the progress made in recent years in fluorescence methods to determine HMs and their species using CDs. First, the strategies to synthesize and purify CDs are reviewed. The photoluminescence principles of CDs and their sensing mechanisms as HMs sensors are then summarized. The binding strategies between CDs and HMs are proposed to provide salient principles to design desirable CD-based HMs sensors. The preparation and merits of “turn-on” and ratiometric CDs for HMs detection with higher accuracy are discussed compared with commonly used “turn-off” sensors. Subsequently, the progress on detecting single HM ions, multi-HMs, and different metal species in solution, and the development of gel/solid-state sensor platforms such as paper-based devices, sensor arrays, hydrogels, polymer films, and ion-imprinted polymers are critically accessed. Furthermore, the advances in the cell, bacterial, plant, and animal bioimaging of HMs with CDs as promising bioimaging reagents are presented. Finally, the challenges and prospects of CDs as HMs sensors in future investigations are discussed.

Detection of lead(II) (Pb2+) ions in water is important for the protection of human health and environment. The growing demand for onsite detection still faces challenges for sensitive and easy-to-use methods. In this work, a novel surface plasmon resonance (SPR) biosensor based on GR-5 DNAzyme and gold nanoparticles (AuNPs) was developed. Thiolated DNAzyme was immobilized on the gold surface of the sensor chip followed by anchoring the substrate-functionalized AuNPs through the DNAzyme-substrate hybridization. The coupling between the localized surface plasmon (LSP) of AuNPs and the surface plasmon polaritons (SPP) on the gold sensor surface was used to improve the sensitivity. The substrate cleavage in the presence of Pb2+ ions was catalyzed by DNAzyme, leading to the removal of AuNPs and the diminished LSP-SPP coupling. The optimal detection limit was 80 pM for the sensor fabricated with 1 μM DNAzyme, corresponding to two or three orders of magnitude lower than the toxicity levels of Pb2+ in drinking water defined by WHO and USEPA. By tuning the surface coverage of DNAzyme, the sensitivity and dynamic range could be controlled. This sensor also featured high selectivity to Pb2+ ions and simple detection procedure. Successful detection of Pb2+ ions in groundwater indicates that this method has the prospect in the onsite detection of Pb2+ ions in water. Given the variety of AuNPs and metal-specific DNAzymes, this detection strategy would lead to the development of more sensitive and versatile heavy metal sensors.

The present work demonstrated and compared the anti-inflammatory effects of celery leaf (CLE) and stem (CSE) extracts. LC-MS-based metabolomics were an effective approach to achieve the biomarker identification and pathway elucidation associated with the reduction in inflammatory responses. The celery extracts suppressed LPS-induced NO production in RAW 264.7 cells, and CLE was five times more effective than CSE. Distinct differences were revealed between the control and celery-treated samples among the 24 characteristic metabolites that were identified. In celery-treated LPS cells, reversals of intracellular (citrulline, proline, creatine) and extracellular (citrulline, lysine) metabolites revealed that the therapeutic outcomes were closely linked to arginine metabolism. Reversals of metabolites when treated with CLE (aspartate, proline) indicated targeted effects on the TCA and urea cycles, while, in the case of CSE (histidine, glucose), the glycolysis and the pentose phosphate pathways were implicated. Subsequently, apigenin and bergapten in CLE were identified as potential biomarkers mediating the anti-inflammatory response.

Despite remarkable progress in disease diagnosis and treatment, coronary heart disease (CHD) remains the number one leading cause of death worldwide. Many practical challenges still faced in clinical settings necessitates the pursuit of omics studies to identify alternative/orthogonal biomarkers, as well as to discover novel insights into disease mechanisms. Albeit relatively nascent as compared to the omics frontrunners (genomics, transcriptomics, and proteomics), omics beyond the central dogma (OBCD; e.g., metabolomics, lipidomics, glycomics, and metallomics) have undeniable contributions and prospects in CHD research. In this bibliometric study, we characterised the global trends in publication/citation outputs, collaborations, and research hotspots concerning OBCD-CHD, with a focus on the more prolific fields of metabolomics and lipidomics. As for glycomics and metallomics, there were insufficient publication records on their applications in CHD research for quantitative bibliometrics analysis. Thus, we reviewed their applications in health/disease research in general, discussed and justified their potential in CHD research, and suggested important/promising research avenues. By summarising evidence obtained both quantitatively and qualitatively, this study offers a first and comprehensive picture of OBCD applications in CHD, facilitating the establishment of future research directions.

Recombinant protein biopharmaceuticals comprise a significant portion of the current drug development landscape. The glycosylation profile of these proteins is a key quality parameter as it can affect their safety, efficacy, and stability. However, glycan analysis is challenging because of the complexity of their structures. To overcome this challenge in achieving accurate glycan identification, cross-identification of N-Glycans by CE-LIF method using two capillary coatings and three labeling dyes was developed in this work. This work explored whether complementary separation capabilities can be achieved using homemade polyvinyl alcohol (PVA) coating and commercial Guarant™ (Guarant) coating in the analysis of N-glycans. Similar separation profiles were observed using the two capillary coatings, and hence the N-glycan GU databases generated by these coatings were comparable and complementary. The performance of cross-validation by labeling with three fluorescent dyes indicated that low covariance of APTS and Turquoise™ labeling can be obtained, and hence these two labeling mechanisms provided better accuracy for the identification of glycans. Superior reproducibility with RSDs less than 1% for all target glycan standards was achieved by the internal standards (IS) method using maltodextrin ladders as additives in the separation buffer. The developed CE-LIF analysis method was applied to the identification of N-glycans in IgG samples.

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen that is found ubiquitously in the environment. It is also the cause of nosocomial infections, which affects patients with cystic fibrosis (CF) and cathether-related infections. Treatment and eradication of P. aeruginosa is an uphill task as it has already developed resistance to many commonly used antibiotics. Some of the resistance mechanisms that P. aeruginosa employ are having low cell wall permeability, developing efflux system to pump antibiotics out, producing enzymes to inactivate antibiotics, modifying antibiotic targets, forming biofilm as a protection layer against antibiotics, and turning into more pathogenic small colony variant form. In addition, P. aeruginosa uses a host of signaling mechanisms, such as secretion system and quorum sensing, to aid its virulence. With numerous resistance mechanisms developed against conventional antibiotics, new strategies to treat P. aeruginosa infection are required. Bacteriophages such as natural bacteria viruses and studies have suggested that they can be used as an alternative to antibiotics for treatment against P. aeruginosa infections. However, phage therapy also shares the same problem with that of antibiotics, i.e., the development and emergence of bacteria resistance by masking or altering surface recognition features, inhibiting phage DNA injection and employing abortive infection (Abi) system. Another alternative treatment strategy is to use antimicrobial peptides, which are small cationic peptides that are naturally found in most organisms’ immune system. These peptides disrupt cell membrane and key cellular processes, which requires major gene alteration if evasion is needed. Hence, lowering likelihood of resistance development. This paper aims to review our current understanding of the clinical implications of P. aeruginosa infections, the mechanisms of antibiotic resistance, phage-inspired and antimicrobial peptide approaches for treatment of P. aeruginosa infections.

A significant portion of the scientific effort has been devoted to the detection of endotoxins in pharmaceutical solutions, as they pose major health threats as contaminants even in minute amounts. Conventional methods based on the biological response of endotoxins have been well-established, but as technology advances, many limitations surfaced in the recent years. As a result, information obtained by chemical analytical methods becomes valuable in crossvalidating these results. In addition to providing an overview on the main strategies for detecting the presence of endotoxins, the biological methods are compared with the chemical techniques. The review also investigates future advances aimed toward a more accurate, reliable, and convenient endotoxin test.

The flame retardant triphenyl phosphate (TPhP) has been widely detected in surface waters. Yet, little information is known regarding its impact on microalgae. We investigated the uptake and toxicity of TPhP on two freshwater microalgae Chlorella vulgaris (CV) and Scenedesmus obliquus (SO) after exposure to 10 μg/l–10 mg/l for 5 days. The presence of microalgae significantly enhanced TPhP degradation, with the final concentrations dropped to 5.5–35.1% of the original concentrations. Most of the medium TPhP were sorbed and transformed by microalgae in just one day. Growth of CV was inhibited in a concentration-dependent manner, whereas growth of SO were only inhibited significantly at 10 mg/l TPhP exposure. Mass spectrometry-based untargeted metabolomics revealed concentration- and species-dependent metabolic responses. Exposure to TPhP in CV resulted in enhanced respiration (increase of fumarate and malate) and osmoregulation (increase of sucrose and myo-inositol), synthesis of membrane lipids (accumulation of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), decrease of lysoglycerolipids, fatty acids, and glyceryl-glucoside). Exposure to TPhP in SO resulted in enhanced osmoregulation (increase of valine, proline, and raffinose) and lipolysis (decrease of MGDG, accumulation of fatty acids, lysophospholipids, and glycerol phosphate). Although chlorophyll a and b contents did not change significantly, decrease of chlorophyll derivatives was observed in both CV and SO at high exposure concentrations. Further bioassays confirmed that CV exhibited enhanced membrane integrity and decreased cellular reactive oxygen species (ROS) possibly as a defense strategy, whereas SO showed disruption of membrane integrity and induction of ROS at 10 mg/l exposure. This study demonstrated the potential of microalgae to remove TPhP in water, and offered new insights for the risk assessment of TPhP on freshwater microalgae using metabolomics.

A simple fluorescence biosensor for rapid and sensitive target microRNA (miRNA) quantification by branched rolling circle amplification (BRCA) is developed in this work. Target miRNA functions as primer to recognize and hybridize with a circle DNA template, initiating rolling circle amplification (RCA) by Phi29 DNA polymerase. The introduction of reverse primers complementary to the RCA products enables isothermal BRCA, in which a large amount of deoxynucleotide (dNTP) were consumed and same number of pyrophosphates (PPi) were produced. In this study, a simple and non-expensively synthesized terpyridine-based Zn(II) complex is utilized as fluorescent probe for selective detection of pyrophosphate (PPi) over dNTP. The PPi generated in this isothermal amplification process efficiently chelates to this terpyridine-Zn(II) complex, forming a highly fluorescent complex, terpyridine-Zn(II)-PPi, whose fluorescence intensity is closely related with the initial target miRNA concentration. The utilization of the isothermal BRCA amplification and direct monitoring of the DNA polymerization by-product, i.e. PPi, for non-label fluorescence detection of miRNA greatly simplify this sensor procedure. This sensor shows a linear response between the fluorescence intensity and the target miRNA concentration from 50 to 500 fM with a detection limit of 25 fM. This much-simplified sensor offers a sensitive and easy-to-use platform for miRNA quantification, and hence may significantly enhance the utilisation of miRNAs as biomarkers in drug discovery, clinical diagnosis and life science research. Ministry of Education (MOE) Financial support of this work by the Ministry of Education (R-143- 000-A14-114 and R-143-000-A14-133) is gratefully acknowledged.

Biochar, produced as a by-product of pyrolysis/gasification of waste biomass, shows great potential to reduce the environment impact, address the climate change issue, and establish a circular economy model. Despite the promising outlook, the research on the benefits of biochar remains highly debated. This has been attributed to the heterogeneity of biochar itself, with its inherent physical, chemical and biological properties highly influenced by production variables such as feedstock types and treating conditions. Hence, to enable meaningful comparison of results, establishment of an agreed international standard to govern the production of biochar for specific uses is necessary. In this study, we analyzed four key uses of biochar: 1) in agriculture and horticulture, 2) as construction material, 3) as activated carbon, and 4) in anaerobic digestion. Then the guidelines for the properties of biochar, especially for the concentrations of toxic heavy metals, for its environmental friendly application were proposed in the context of Singapore. The international status of the biochar industry code of practice, feedback from Singapore local industry and government agencies, as well as future perspectives for the biochar industry were explained.

Profiles of combat injuries worldwide have shown that penetrating trauma is one of the most common injuries sustained during battle. This is usually accompanied by severe bleeding or hemorrhage. If the soldier does not bleed to death, he may eventually succumb to complications arising from trauma hemorrhagic shock (THS). THS occurs when there is a deficiency of oxygen reaching the organs due to excessive blood loss. It can trigger massive metabolic derangements and an overwhelming inflammatory response, which can subsequently lead to the failure of organs and possibly death. A better understanding of the acute metabolic changes occurring after THS can help in the development of interventional strategies, as well as lead to the identification of potential biomarkers for rapid diagnosis of hemorrhagic shock and organ failure. In this preliminary study, a metabolomic approach using the complementary platforms of nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography coupled with mass spectrometry (LC-MS) was used to determine the metabolic changes occurring in a porcine model of combat trauma injury comprising of penetrating trauma to a limb with hemorrhagic shock. Several metabolites associated with the acute-phase reaction, inflammation, energy depletion, oxidative stress, and possible renal dysfunction were identified to be significantly changed after a thirty-minute shock period.

Emerging cellulose nanomaterials extracted from agricultural biomasses have recently received extensive attention due to diminishing fossil resources. To further reduce the carbon footprints and wastage of valuable resources, additive manufacturing techniques of new nanocellulosic materials have been developed. Studies on the preparation and characterization of 3D-printable functional nanocellulosic materials have facilitated a deeper understanding into their desirable attributes such as high surface area, biocompatibility, and ease of functionalization. In this critical review, we compare and highlight the different methods of extracting nanocellulose from biorenewable resources and the strategies for transforming the obtained nanocellulose into nanocomposites with high 3D printability. Optimistic technical applications of 3D-printed nanocellulose in biomedical, electronics, and environmental fields are finally described and evaluated for future perspectives.

A simple approach based on calcination treatment of diethylenetriaminepentaacetic acid (DTPA) was developed to prepare water-soluble nitrogen doped carbon nanoparticles (N-CNPs) with a high quantum yield of approximately 53.7%. The fluorescence of N-CNPs could be quickly and efficiently quenched by Cr(VI) rather than Cr(III) based on an inner filter effect (IFE) process. The addition of ascorbic acid (AA) can recover the intensity of fluorescence of the N-CNP–Cr(VI) system through the reduction of Cr(VI) to Cr(III) and inhibit the IFE process between N-CNPs and Cr(VI) (turn-on). Accordingly, an efficient N-CNP based fluorescent probe for sensitive and selective sensing of Cr(VI) ions and L-ascorbic acid (AA) has been established. The proposed fluorescence sensor displays excellent performance for Cr(VI) determination in the range from 0.5 to 160 μmol L−1 (R2 = 0.998) with a detection limit down to 0.15 μmol L−1. Moreover, the observed linear response concentration range was from 1 to 400 μmol L−1 for AA with a detection limit as low as 0.13 μmol L−1. The fluorescent probe was successfully applied to detect Cr(VI) concentration in different water samples and AA concentration in human serum samples.

A generalized strategy for developing a hybrid two-dimensional nanostructured dual T

With possible food crises looming in the near future, urban farming, including small-scale community and home gardens for home consumption, presents a promising option to improve food security in cities. These small-scale farms and gardens often use planter boxes and raised beds filled with lightweight soil or potting mixes. While previous studies on biochar focused on its application on large-scale contiguous farmlands, this study aimed to evaluate the suitability of biochar as a partial soil substitute to produce a durable and lightweight soil-biochar mix for small-scale urban farms. The effects of biochar on the chemical properties of the soil-biochar mix, crop yield and, particularly, crop nutrients and metabolic content were assessed. A germination test using pak choi seeds (Brassica rapa L. cultivar group Pak choi, Green-Petioled Form) showed that the biochar contained phytostimulants. Through a nursery pot experiment over four growth cycles, biochar treatments performed better than pure soil at retaining water-soluble NO3- and K+ ions, but were worse at retaining PO43- ions. Nonetheless, despite its positive effect on soil NO3- retention, biochar application did not improve crop yield significantly when the application rate varied from 0% to 60% (v/v). Untargeted metabolomic analyses showed that biochar application may increase the production of carbohydrates and certain flavonoids and glucosinolates. The results of this study showed that biochar can potentially be used to improve pak choi nutritional values and applied in large quantity to obtain a lightweight soil mix for urban farming.

In this work, a novel electrochemical aptasensor based on Fe-based MOFs was fabricated. To enhance sensitivity to the detection of antibiotics, NH2-MIL-101(Fe)/CNF@AuNPs was synthesized by a combination of hydrothermal, electrospinning, pyrolysis and electrodeposition methods. Subsequently aptamer could be attached to the NH2-MIL-101(Fe)/CNF@AuNPs through “Au-S” bonds. The electrical signals generated from the interaction between antibiotics and aptamers were amplified by the NH2-MIL-101(Fe)/CNF@AuNPs aptasensor, resulting in a significant current/impedance response. Thus, signal generation and amplification were successfully realized. In addition, the Box-Behnken Design (BBD) strategy was adopted to optimize the detection conditions and greatly reduce experimental errors. Under optimized conditions, the tetracycline concentration detected by the sensor had a linear relationship with the impedance in the range of 0.1–105 nM TC. The lowest detection limit was 0.01 nM. NH2-MIL-101(Fe)/CNF electrospinning aptasensor exhibited good selectivity and stability. Furthermore, quantitative detection of tetracycline was achieved in real water samples. The sensor reported here could become a promising new strategy for detecting tetracycline in environmental water samples in the future.

In this work, we identified the problem faced by conventional successive ionic layer adsorption and reaction (SILAR) process in producing uniform nickel hydroxide films as the homogeneous precipitation reaction in water. Subsequently we proposed a novel SILAR recipe with a modified rinsing step and successfully demonstrated, for the first time, a layer-by-layer coating of uniform nickel hydroxide thin film without surface structures or agglomerated precipitates. In addition, we explored and demonstrated the capability of the proposed SILAR process in incorporating additional element such as aluminum into the nickel hydroxide film. The aluminum incorporated nickel hydroxide film shows improved electrochromic stability evidenced by reducing the degradation in coloration efficiency from 46% to 6%. The average coloration efficient is reported as 22 cm2/C and the response time is 4.5 s for bleaching and 4 s for coloration.