Power requirements represent a critical challenge for wearable sensors. Self-powered sensing systems enabled by miniaturized energy-storage devices (MESDs) offer a promising solution. However, the proliferation of MESDs inevitably generates electronic waste (e-waste), which causes environmental concerns. Transient electronics that degrade into eco-friendly residuals provide opportunities for the development of green power sources. Herein, flexible e-waste-friendly power sources based on degradable MXene films were developed for the integration of wearable, self-powered biomedical sensors. The proposed transient MXene film-based supercapacitors (TMFSCs) possess good energy storage capability and mechanical flexibility and can be completely degraded into eco-friendly residuals within minutes. Furthermore, a wearable self-powered biomedical smart sensor was designed for real-time monitoring of pulse signals in real-life scenarios, and the obtained pulse rate is conducive to early evaluation of human health. Collectively, TMFSCs are considerably competitive for future eco-friendly flexible MESDs toward next-generation sustainable wearable and portable sensing electronics.

Plasmonic metasurfaces (PMs) are emerging as a powerful platform for optical biosensing due to their unique sensing capabilities. However, in practical applications involving complex matrices, nonspecific adsorption at the sensing interface generally causes false-positive signals, which considerably compromise the accuracy of detection. To address this limitation, we propose a cadmium ion (Cd2+)-driven "turn-off" biosensing strategy by leveraging the precise closing of plasmonic nanocavities constructed via the coupling of nanohole array-based PMs and gold nanoparticles (AuNPs), enabling the detection of trace Cd2+ in both serum and urine samples. Upon Cd2+ binding, the aptamers (Cd2+-specific single-stranded DNA) undergo a conformational change to a stem-loop structure, which dislodges the AuNPs from the PM surface, thereby inducing a blueshift in the resonance dip of the PM chip. This sensing mechanism allows for ultrasensitive Cd2+ detection in complex matrices while effectively mitigating signal errors arising from nonspecific adsorption. Crucially, the "turn-off" sensing mechanism endows the sensor with excellent chip regeneration capability. Experimental results demonstrate a wide linear detection range from 0.05 pg/L to 50 μg/L, a high correlation coefficient of R2 = 0.999, and an ultra-low detection limit of 3.55 fg/L. This strategy allows extension to other heavy metal ions or biomolecules via tailored aptamer and metasurface design.

Organophosphorus compounds (OPCs) are widely applied in diverse industries, yet their continuous release across the full life cycle poses significant risks to human health and ecosystems. Current research on OPCs is largely limited to organophosphate esters (OPEs), with scarce attention paid to structurally diverse OPCs─creating critical gaps in comprehensive environmental screening and risk assessment. To address this gap and facilitate robust OPC analysis, we curated and integrated OPC-related cheminformatics data from academic and public sources, constructing a structured library of OPCs classified by chemical structure. We further prioritized high-production-volume (HPV) OPCs, which are pivotal for targeted environmental research and regulatory focus. A key analytical advancement herein is the development of a lightweight deep learning model based on graph neural networks (GNNs), which extracts molecular structural features to predict tandem mass spectra (MS/MS) data for OPCs. This model directly overcomes the major bottleneck of limited reference MS/MS for most OPCs in existing libraries. These curated resources and predictive capabilities are embedded into DCOP (Database of Chemicals for Organophosphorus)─a high-quality, large-scale, open-access software platform integrating search query, MS/MS prediction, and data download functions. DCOP fills unmet needs in OPC research, providing a valuable tool to advance environmental monitoring, risk assessment, and regulatory decision-making for OPCs globally.

Plasmonic biosensors hold an enticing prospect for drug testing and disease diagnostics as they have demonstrated impressive superiority in ultrasensitive and label-free detection. In this paper, we demonstrate a plasmonic sensing strategy for the heparin assay by leveraging near-field and far-field competitive couplings between gold (Au) nanoparticles (NPs) and nanodisk (ND) array. Specifically, the near-field coupling of the ND array and Au NPs binding to its surface results in a spectral redshift. Meanwhile, the far-field coupling of dispersed Au NPs in mixed solution and ND array induces a spectral blueshift. As a result, heparin concentration-dependent near-field and far-field competitive couplings determine the direction and amount of the spectral shift. Compared with existing detection technologies, this sensing strategy also presents a balance point, enabling rapid assessment of heparin dosage safety. Additionally, an exceptionally wide dynamic range of 10-4 μg/mL to 103 μg/mL, a low detection limit of 29 pg/mL, and excellent selectivity are demonstrated. The analysis of heparin in serum further underscores this assay approach's potential for advancing disease diagnosis and therapeutic monitoring at the point of care.

A cost-effective AuNPs-coupled PM platform for highly sensitive and selective cadmium ion (Cd2+) detection is developed, in which Cd2+-induced conformational switching of aptamers from single-stranded DNA to a stem-loop structure is utilized, preventing AuNPs from binding to the PM surface and reducing wavelength shift. Furthermore, the contribution of localized coupling effects between AuNPs and various positions on the PM surface to the change of the sensing signal is revealed, offering insights into AuNPs-enhanced PM sensing compared to traditional effective refractive index theory. Our proposed sensing platform enables the detection of Cd2+ in ultrapure water over a broad concentration range from 10 pg/L to 10 mg/L with excellent linearity, achieving a detection limit of 3.72 pg/L, which is approximately 6 orders of magnitude lower than the clinically required concentration. Moreover, the sensing method demonstrates excellent recovery rates and resistance to interferences in complex Cd2+-spiked urine and serum samples. Due to the low-cost, scalability, and ease of fabrication of both AuNPs and PM chips, as well as the universal applicability of aptamers to target various analytes, this biosensing platform holds the potential for high-throughput detection of other heavy metal ions, environmental pollutants, and disease biomarkers.

The selective activation of C=O bonds was the key challenge in the field of biomass utilization. Researchers worked on this purpose by developing high-active and high-selective catalysts. In this study, a Pd1/α-MoC single-atom catalyst was synthesized and applied in selective hydrogenation of biomass-derived furfural with 96.7 % conversion and 92.4 % selectivity under a near-room temperature. With various characterizations, the formation of Pd single-atom sites over the surface of α-MoC was confirmed. Then, the dominant structure of Pd single-atom site and the reaction pathway were proposed with experimental and Density Functional Theory (DFT) studies. Compared with undecorated α-MoC, the introduction of Pd single-atom species significantly altered the reaction mechanism from Meerwein-Ponndorf-Verley (MPV) process. Moreover, the Pd single-atoms loading on α-MoC(111) surface notably reduced the energy barriers of H2 activation and C=O bond hydrogenation, which may lead to the improving catalytic performance of α-MoC based catalyst. Hence, this investigation could provide a new strategy and understanding for the development of high-active and low-cost catalysts.

As a commonly used plasma diagnostic method, the spectral analysis methodology generates a large amount of data and has a complex quantitative relationship with discharge parameters, which result in low accuracy and time-consuming operation of traditional manual spectral recognition methods. To quickly and efficiently recognize the discharge parameters based on the collected spectral data, a one-dimensional (1D) deep convolutional neural network was constructed, which can learn the data features of different classes of ethylene plasma spectra to obtain the corresponding discharge parameters. The results show that this method has a higher recognition accuracy of higher than 98%. This model provides a new idea for plasma spectral diagnosis and its related application.

The sensitivity and repeatability are crucial for the practical application of electrochemical sensors. Many studies have focused on sensing materials and electrode structure to enhance sensitivity and repeatability rather than insulating layers. In this paper, polyaniline (PANI) microelectrode arrays were prepared to explore the influence of the insulating layer on sensitivity and repeatability of electrochemical sensors. The effects of different types of insulating layers, the sizes of the electrodes, and the thicknesses of the insulating layers were studied by experiment and simulation. The research findings indicated that the kind of organic insulating layers (Polyimide (PI) and SU-8) did not have a significant effect on the performance of the sensors. However, as the electrode area increased, the PANI film deposited on the electrode exhibited improved uniformity and density, leading to significant improvements in sensitivity and repeatability of the sensors. Additionally, the thickness of the insulating layer also had a significant impact on the performance of the device. The microelectrode with thinner insulating layers exhibited improved performance in sensitivity, repeatability and signal-to-noise ratio. The research findings indicated that increasing the electrode size and reducing the thickness of the insulating layer led to a more uniform and dense PANI film, resulting in an array electrode that exhibits excellent performance and remarkable repeatability.

By using thioflavin T (ThT) as displacement -based fluorescent probes, three kinds of aptasensors were constructed for rapid detection of three kinds of small molecules such as ochratoxin A (OTA), aflatoxin B1 (AFB1) and adenosine. In the absence of target molecule, ThT bound with the aptamer to form an aptamer-ThT complex and exhibited a significant fluorescence response. Upon the addition of target molecule, because of the higher affinity between target and aptamer than that between ThT and the aptamer, ThT was displaced by the target molecule from the aptamer-ThT complex, resulting in weakened fluorescence signal. Based on this principle, the target molecule could be detected quantitatively. Further study through circular dichroism spectra showed that there was no significant change in the conformation of the aptamer after addition of ThT or target molecules. The stoichiometric ratios of ThT to OTAapt, AFB1apt and Adeapt measured through the method of equimolar continuous variation was 1 : 1, 1 : 1 and 2 : 1, respectively, and their dissociation constants were all larger than those between the target molecule and its aptamer. Therefore, the principle of this detection method was the displacement of fluorescent probe (ThT) in aptamer-ThT complex by target molecule, resulting in decrease of fluorescence intensity. Under optimal experimental conditions, the limits of detection (LODs) were 0.8 nmol/L for OTA, 1.3 nmol/L for AFB1, and 0.10 mu mol/L for adenosine, respectively. This method was label-free, simple to operate, with low cost, good selectivity and high sensitivity. The developed assay kit based on this method could be used for actual sample detection.

Water quality is affected due to the intensification of agricultural activities, causing algae and bacterial eutrophication, contributing to drinking water’s taste and odor (T&O) issues, and producing undesirable odorants and metabolites. Water samples were taken from the reservoir (point 1) and the pipeline entering the water treatment plant (point 2). The change in water quality was evaluated by fluorescence, which showed an increase in the concentration of T&O and natural organic matter (NOM). A modified biomass composite material (MBCM) was synthesized to mitigate the issue using SiO2/Al2O3 and AlOOH. The synthesized MBCM has a core–shell, petal-like symmetric structure with micro and meso pores. In the biomass core, composite material SiO2/Al2O3 provides micropores for the adsorption of geosmin (GSM) and free di-methylisoborneol (2-MIB). At the same time, AlOOH surrounds itself as a shell structure less dense than the core, seizing humic acid (HA) and 2-MIB bound with (NOM). Studies analyzed that the correlation of protein substance with 2-MIB has physical entanglement. MBCM proved effective in eliminating the physical entanglement of pollutants, making enriched sediments and removing 91.10%, 82.50%, and 52.36% GSM, 2-MIB, and HA, respectively, in a notable 10-minute adsorption time. The fluorescence spectrum shows a sizable reduction in intensity after adsorptive treatment. MBCM was also successfully regenerated using alkaline treatment. By the concept of adsorption-coagulation, MBCM had eliminated the T&O and NOM entanglement, enriched the sediments, increased sedimentation speed, reduced overall water treatment plant process length, and eliminated secondary pollution issues.

Biotoxins, particularly mycotoxins, marine toxins, and bacterial food toxins, have emerged as major threats in food, feed, seafood, and medicine fields. They have potential carcinogenic, teratogenic, and mutagenic effects on humans, occasionally causing high mortality and morbidity. One of the evident issues is related to the ever-growing use of fast food and demand for prepared food without proper acknowledgment of associated toxins. Hence, developing better methods for monitoring biotoxins is of great significance. Recently, biosensors have been increasingly used due to their simple and quick detection procedure, less sample volume, low cost, and so on. This study aimed to extrapolate the application of biosensors in biotoxin detection in recent years, with particular emphasis on their optical, electrochemical, piezoelectric, and photothermal applications. Further, different detection platforms were integrated as multimodal combination biosensors for biotoxins to meet the requirement of highly accurate technologies. This study examined the major challenges faced by biosensors and provided novel insights for improving the technology in food safety.

目的 研究三七炮制前后挥发性成分的变化,从挥发性成分角度阐释生、熟三七的物质基础.方法 利用顶空-气相色谱质谱联用技术对生、熟三七中挥发性成分进行比较分析.以He为载气,采用DB-FFAP(30 m×0.25 mm,0.25 μm)极性色谱柱分离,EI离子源电离,结合NIST 11.L质谱库对化合物进行鉴定.结果 生、熟三七中分别鉴定出 103 和 126 种挥发性成分,其中相对含量最高的是萜烯类物质,分别占总挥发性成分的 51.75%和50.16%.从三七中新检测出乙醛等 15 种小分子化合物.熟三七中检测到 17 种特有的挥发性成分.结论 本研究较为全面地分析了生、熟三七中挥发性成分的主要异同,从挥发性成分角度阐释三七"生消熟补"的药用机制,为三七炮制规范及质量控制提供重要的数据支持.

Aluminum hydroxide adjuvants are widely used in human vaccines, such as diphtheria, tetanus, hepatitis A and hepatitis B vaccines. The adsorption of antigens on aluminum hydroxide adjuvants determines the immune boosting effect of vaccines, but it is not clear how changes in physicochemical properties resulting from the production and formulation processes affect the adsorption of aluminum hydroxide adjuvants with antigens. In this study, the commercial aluminum hydroxide adjuvant Alhydrogel® was pretreated by commonly used processes such as autoclaving and calcination, and the changes of aluminum hydroxide adjuvant in physicochemical properties during the treatment were then comprehensively characterized. The adsorption of ovalbumin (OVA) with treated Alhydrogel®, was also investigated, it was found that the decrease in specific surface area caused by the autoclaving process reduced the adsorptive capacity of the antigen, and the adsorptive strength of antigen was decreased only when the surface hydroxyl groups and chemically bound water of adjuvant were reduced by calcination. These findings help to optimize the production and formulation process of adjuvants for the rational regulation of antigen adsorption in vaccines.

Zwitterionic polymers have emerged as promising trans-mucus nanocarriers due to their superior antifouling properties. However, for pH-sensitive zwitterionic polymers, the effect of the pH microenvironment on their trans-mucus fate remains unclear. In this work, we prepared a library of zwitterionic polydopamine-modified silica nanoparticles (SiNPs-PDA) with an isoelectric point of 5.6. Multiple-particle tracking showed that diffusion of SiNPs-PDA in mucus with a pH value of 5.6 was 3 times faster than that in mucus with pH value 3.0 or 7.0. Biophysical analysis found that the trans-mucus behavior of SiNPs-PDA was mediated by hydrophobic and electrostatic interactions and hydrogen bonding between mucin and the particles. Furthermore, the particle distribution in the stomach, intestine, and lung demonstrated the pH-mediated mucus penetration behavior of the SiNPs-PDA. This study reveals the pH-mediated mucus penetration behavior of zwitterionic nanomaterials, which provides rational design strategies for zwitterionic polymers as nanocarriers in various mucus microenvironments.

Catalytic conversion of biomass-derived levulinic acid (LA) into high-valued 5-methylpyrrolidones has become an attractive case in studies of biomass utilization. Herein, we developed a disordered mesoporous Pt/MNS catalyst for this reductive amination process under room temperature and atmospheric pressure of hydrogen. The disordered mesoporous structures in support of Pt/MNS catalyst led the formation of highly dispersed Pt species via confinement effect, providing high specific area for enhancing the catalytic sites. With the synergistic effect between highly dispersed Pt species and mesoporous structures, 5-methylpyrrolidones were successfully synthesized from biomass-derived LA and primary amines with high selectivity. Mechanism studies indicated that introducing protonic acid would promote the reductive-amination process, and enamine intermediates could be detected during the in-situ DRIFT tests. Density functional theory (DFT) calculation confirmed that the hydrogenation of enamine intermediate was more accessible than that of imide intermediates, leading the excellent performance of the Pt/MNS catalyst. This work provided a green method to produce 5-methylpyrrolidone and revealed the impact of catalyst structural characteristics on the reaction process.

The zeolitic imidazole framework with a leaf-shaped morphology (ZIF-L) has a wide range of promising applications in gas storage, battery materials, catalytic reactions, and optoelectronic devices due to its planar leaf-like structure and large surface area. However, the low conductivity, weak catalytic activity, and poor stability in the water dielectric medium of ZIF-L limit its further practical application. To solve these problems, we added the conductive polymer heterocyclic poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to ZIF-L for the sensitive detection of dopamine (DA). The synthesized composite ZIF-L/PEDOT:PSS (ZIF-L/PEDOT) not only retained the surface morphology of ZIF-L but also exhibited excellent electrochemical properties. The higher electrical conductivity of ZIF-L/PEDOT than that of ZIF-L was due to the enhanced electron transfer at the interface between ZIF-L and PEDOT:PSS. As a result, we developed an electrochemical biosensor based on the ZIF-L/PEDOT composite, which has a limit of detection of 7 nM for DA and a wide linear range from 25 nM to 500 μM. Furthermore, the current drop was negligible after 28 days, proving that the biosensor has excellent stability. Based on the above-mentioned outstanding performance, the ZIF-L/PEDOT-based biosensor was successfully used to detect DA in human serum samples. These results demonstrated that ZIF-L/PEDOT is expected to play an essential role in disease detection.

This study describes a quencher-free fluorescent aptasensor for ochratoxin A (OTA) detection using the specific quenching ability of guanine for fluorescein (FAM) molecules based on photo-induced electron transfer (PIET). In this strategy, OTA is detected by monitoring the fluorescence change induced by the conformational change of the aptamer after target binding. A new shorter OTA aptamer compromising three guanine bases at the 5′ end was used in this study. This new aptamer, named G3-OTAapt1-FAM (F1), was labeled with FAM on the 3′ end as a fluorophore. In order to increase the binding affinity of the aptamer and OTA, G3-OTAapt2-FAM (F2) was designed; this added a pair of complementary bases at the end compared with F1. To prevent the strong self-quenching of F2, a complementary chain, A13, was added. Although the F1 aptasensor was simpler to implement, the sensitivity of the F2 aptasensor with A13 was better than that of F1. The proposed F1 and F2 sensors can detect OTA with a concentration as low as 0.69 nmol/L and 0.36 nmol/L, respectively.

G-quadruplexes have received significant attention in aptasensing due to their structural polymorphisms and unique binding properties. In this work, we exploited the fluorescence-quenching properties of G-quadruplex to develop a simple, fast, and sensitive platform for fluorescence detection of ochratoxin A (OTA) and potassium ions (K+) with a label-free fluorophore and quencher strategy. The quenching ability of G-quadruplex was confirmed during the recognition process after the formation of the G-quadruplex structure and the quenching of the labeled fluorescein fluorophore (FAM). The fluorescence-quenching mechanism was studied by introducing specific ligands of G-quadruplex to enhance the quenching effect, to show that this phenomenon is due to photo-induced electron transfer. The proposed fluorescence sensor based on G-quadruplex quenching showed excellent selectivity with a low detection limit of 0.19 nM and 0.24 µM for OTA and K+, respectively. Moreover, we demonstrated that our detection method enables accurate concentration determination of real samples with the prospect of practical application. Therefore, G-quadruplexes can be excellent candidates as quenchers, and the strategy implemented in the study can be extended to an aptasensor with G-quadruplex.

The interaction between the aluminum salt-based adjuvants and the antigen in the vaccine formulation is one of the determining factors affecting the immuno-potentiation effect of vaccines. However, it is not clear how the intrinsic properties of the adjuvants could affect this interaction, which limits to benefit the improvement of existing adjuvants and further formulation of new vaccines. Here, we engineered aluminum oxyhydroxide (AlOOH) nanorods and used a variety of antigens including hepatitis B surface antigen (HBsAg), SARS-CoV-2 spike protein receptor-binding domain (RBD), bovine serum albumin (BSA) and ovalbumin (OVA) to identify the key physicochemical properties of adjuvant that determine the antigen adsorption at the nano-bio interface between selected antigen and AlOOH nanorod adjuvant. By using various physicochemical and biophysical characterization methods, it was demonstrated that the surface hydroxyl contents of AlOOH nanorods affected the adsorptive strength of the antigen and their specific surface area determined the adsorptive capacity of the antigen. In addition, surface hydroxyl contents had an impact on the stability of the adsorbed antigen. By engineering the key intrinsic characteristics of aluminum-based adjuvants, the antigen adsorption behavior with the aluminum adjuvant could be regulated. This will facilitate the design of vaccine formulations to optimize the adsorption and stability of the antigen in vaccine.

The suspension stability of aluminum-based adjuvant (Alum) plays an important role in determining the Alum-antigen interaction and vaccine efficacy. Inclusion of excipients has been shown to stabilize antigens in vaccine formulations. However, there is no mechanistic study to tune the characteristics of Alum for improved suspension stability. Herein, a library of self-assembled rice-shaped aluminum oxyhydroxide nanoadjuvants i.e., nanorices (NRs), was synthesized through intrinsically controlled crystallization and atomic coupling-mediated aggregations. The NRs exhibited superior suspension stability in both water and a saline buffer. After adsorbing hepatitis B surface antigen (HBsAg) virus-like particles (VLPs), human papillomavirus virus (HPV) VLPs, or bovine serum albumin, NR-antigen complexes exhibited less sedimentation. Further mechanistic study demonstrated that the improved suspension stability was due to intraparticle aggregations that led to the reduction of the surface free energy. By using HBsAg in a murine vaccination model, NRs with higher aspect ratios elicited more potent humoral immune responses. Our study demonstrated that engineered control of particle aggregation provides a novel material design strategy to improve suspension stability for a diversity of biomedical applications.