Real Human Serum Research Articles

Time-Resolved Levodopa Cascade Polymerization Tuned by Bimetallic MOF Fluorescent Nanozyme and Boric Acid for Butyrylcholinesterase Activity Dual-Mode Assay.

A ratiometric fluorescence-photothermal dual-mode assay method is constructed for the detection of butyrylcholinesterase (BChE) activity based on time-resolved levodopa (L-DOPA) cascade polymerization. First, a newly designed bimetallic metal-organic framework (MOF), Eu/Co-DPA (DPA: pyridine-2,6-dicarboxylic acid), is screened out as a fluorescent nanozyme with high catalytic activity and superior luminescence properties. In the presence of boric acid (BA), L-DOPA forms BA-esterified L-DOPA, which is catalyzed by Eu/Co-DPA to form the oligomers with strong blue fluorescence. Meanwhile, the red fluorescence of Eu/Co-DPA is quenched by the oligomers, generating a sensitive turn-on/off ratiometric fluorescence response. As polymerization time increases, Eu/Co-DPA cleaves the borate ester bonds to expose the catechol structures of the oligomers, which facilitates the further oxidation and polymerization of the oligomers, promoting the formation of poly(L-DOPA) nanoparticles with a high photothermal conversion efficiency (30.33%). Then, by using thiocholine (butyrylthiocholine enzymolysis product) to inhibit the catalytic activity of Eu/Co-DPA, BChE activity is detected through the change in fluorescence and photothermal dual signals. Both assay modes have low detection limits (0.021 and 0.024 U L-1) and high accuracy (93.3-105.3% recovery). The detection results of real human serum indicate that both assay modes show 100.0% agreement with the standard method. To our knowledge, this work first combines bimetallic MOFs and a BA regulator to tune the structure of L-DOPA polymers, providing a pathbreaking paradigm for preparing catecholamine-based fluorescence-photothermal organic polymers.

A cost-effective and sensitive Au/6-mercaptohexanol/CNBr modified immunosensor approach for adiponectin analysis

This research aimed to develop a method for analyzing adiponectin using a label-free impedimetric indium tin oxide-polyethylene terephthalate (ITO-PET) immunosensing system. A simple and stable process to design a bioelectrode modified with gold (Au)/6-mercaptohexanol (6-MH)/cyanogen bromide (CNBr)/anti-adiponectin and its biocompatibility with adiponectin was investigated. The immunosensor performance, optimization tests, and immobilization steps were all monitored and analyzed using Electrochemical Impedance spectroscopy (EIS) and cyclic voltammetry (CV). Scanning Electron microscopy (SEM) examined the surface morphology of this biosensor during its immobilization process. Testing the developed biosensor with real human serum samples allowed for an evaluation of its clinical performance. The proposed immunosensor demonstrated high repeatability, reproducibility (RSD%: 4.37 %), long storage stability, and reusability (preserving 85 % of activity in the third regeneration step), along with a low limit of detection for adiponectin antigen and a wide range of linear values. The sensor suggested a linear detection range of 0.25 pg/mL to 500 pg/mL. The limit of detection (LOD) was found to be 0.20 pg/mL, and the limit of quantification (LOQ) was determined to be 0.66 pg/mL. It appears that the biosensor decorated with Au/6-MH/CNBr could be a good choice for the selective determination of adiponectin protein, according to the statistical data.

Rational construction of porous cobalt nanoparticle integrated nitrogen doped hollow carbon nanostructures for peptide agonist exendin-4 biosensing

In this study, we designed a point-of-care (POC) testing electrochemical biosensor using an integrated biosensing assay based on hollow-like nitrogen-doped carbon nanostructures combined with cobalt nanoparticles (Co@HNCNs, Co3O4@HNCNs, and CoP@HNCNs). These are functionalized with Anti-Exendin-4 Antibodies (Anti-Ex-4-Abs) and Bovine Serum Albumin (BSA) to create sensitive probes (Co@HNCNs/Anti-Ex-4-Abs/BSA, Co3O4@HNCNs/Anti-Ex-4-Abs/BSA, and CoP@HNCNs/Anti-Ex-4-Abs/BSA) for the ultrasensitive detection of exendin-4 (Ex-4), a peptide agonist used in the treatment of type 2 diabetes mellitus (T2DM). Among the cobalt-based carbon nanostructures, the Co3O4@HNCNs/Anti-Ex-4-Abs/BSA nanoprobe demonstrated superior ability to specifically recognize Ex-4. This was indicated by a significant decrease in the chronoamperometric (CA) i-t current response, facilitating low-level detection of Ex-4. The nanoprobe was capable of detecting Ex-4 concentrations ranging from 1.0 to 90.0 pM, with a sensitivity of 0.60 μA/pM and a limit of detection (LOD) of 0.46 pM (S/N = 3). Furthermore, the Co3O4@HNCNs/Anti-Ex-4-Abs/BSA nanoprobes demonstrated the ability to detect nanomolar levels of Ex-4 in blood serum and urine samples, achieving satisfactory recovery rates of 96–104%. The proposed electrostatic interaction chemistry approach establishes a remarkable platform for constructing a peptide agonist biosensor that is effective for detecting Ex-4 in real human serum and urine samples.

In situ construction of oriented Au/PPy nanorod arrays-based aptasensor for fast and ultrasensitive determination of thrombin

The dynamic changes in coagulation function indicators provide important references for early warning, disease progression, and prognosis evaluation of clinical cardio-cerebrovascular disease (CCVD) patients. However, current assay methods, such as enzyme-linked immunosorbent assay (ELISA), fluorescence immunoassay and colorimetry, are time-consuming, require bulky equipment, tedious operations, and long analytical period, which are difficult in achieving an on-site and rapid detection. To address above issues, we proposed an ultrasensitive and fast-responded aptasensor for the detection of a typical coagulation function indicator (Thrombin, Tob) through constructing a unique oriented Au/polypyrrole (PPy) nanorod arrays. This architecture has provided both high electrocatalysis and abundant active sites as the signal transfer and DNA carrier. Meanwhile, through the specific DNA-binding representative design, we also designed a target-induced chain release strategy based on the competitive interaction between Tob and cDNA, which remarkably accelerated the Tob recognition process. This aptasensor enables to present an ultralow detection limit of 3 fg/mL and fast detection time of 20 min in real human serum samples, together with the favorable repeatability, stability and anti-interference ability for early warning and prognosis prediction of CCVD. It is promising that this aptasensor can be extended to analyze more disease markers through the change of different bases sequence of the applied DNA stands, which will provide an on-site and convenient technique and device for clinical disease diagnosis.

Single-Molecule adenosine detection and chiral selectivity by DNA aptamer conformational changes using α-Hemolysin nanopore

Nucleic acid aptamers, which are short single-stranded RNA or DNA molecules, undergo conformational changes upon recognizing small molecules. However, their structural characterization is challenging due to the flexibility of single-stranded oligonucleotides. Nanopores provide a sensitive method for single-molecule analysis of molecular conformational changes as they transport through the pore. In this study, we employed α-hemolysin (α-HL) nanopore with high spatiotemporal resolution to investigate the conformational changes of DNA aptamer (ADO-23) upon binding to adenosine (Ado) molecules. Unlike the events generated by the aptamer alone, the DNA-Ado complex produced two distinct new characteristic events, indicating the formation of two unique secondary structures. By analyzing current events, the structures formed by the DNA-Ado complex were speculated to be hairpin DNA and G-quadruplex (G4) DNA. Furthermore, we demonstrated the potential of the aptamer as a chiral selector within the nanopore. The results showed that the aptamer specifically bound to D-Ado and not to L-Ado. Finally, we realized specific and sensitive detection of small molecule Ado by α-HL pore, with a detection limit as low as 10.5 nM, and successfully applied it to the detection of real human serum samples. The nanopore platform provides a powerful tool for studying small molecule-biomolecule conformational changes, and we constructed sensors for detecting adenosine through the aptamer. This work also offers a promising new approach to the recognition of enantiomers at the single-molecule level.

A Photoelectrochemical Biosensor Mediated by CRISPR/Cas13a for Direct and Specific Detection of MiRNA-21.

Direct detection of miRNA is currently limited by the complex amplification and reverse transcription processes of existing methods, leading to low sensitivity and high operational demands. Herein, we developed a CRISPR/Cas13a-mediated photoelectrochemical (PEC) biosensing platform for direct and sensitive detection of miRNA-21. The direct and specific recognition of target miRNA-21 by crRNA-21 eliminates the need for pre-amplification and reverse transcription of miRNA-21, thereby preventing signal distortion and enhancing the sensitivity and precision of target detection. When crRNA-21 binds to miRNA-21, it activates the trans-cleavage activity of CRISPR/Cas13a, leading to the non-specific cleavage of biotin-modified DNA with uracil bases (biotin-rU-DNA). This cleavage prevents the biotin-rU-DNA from being immobilized on the electrode surface. As a result, streptavidin cannot attach to the electrode via specific biotin binding, reducing spatial resistance and causing a positively correlated increase in the photocurrent response. This Cas-PEC biosensor has good analytical capabilities, linear responses between 10 fM and 10 nM, a minimum detection limit of 9 fM, and an excellent recovery rate in the analysis of real human serum samples. This work presented an innovative solution for detecting other biomarkers in bioanalysis and clinical diagnostics.

A cathodic photoelectrochemical self-powered aptasensor for ratiometric detection of cortisol based on PCN-224@graphene nanocomposites

Cathodic photoelectrochemical (PEC) sensors have garnered considerable research interest in bioanalysis for their ability to mitigate interference from photogenerated holes in concomitant reducing substances, but there remains a challenge to improve detection accuracy with rational strategies. In this study, a ratiometric assay was developed for cathodic PEC aptasensing of cortisol (COR), a stress hormone. Under visible-light exposure, porphyrin-based metal organic framework (PCN-224) and poly(diallyldimethylammonium chloride)-modified reduced graphene oxide (PrGO) composites were utilized as photoactive materials, enabling cathodic photocurrent production at 0 V. The spatially resolved dual photocathodes were combined with a COR-binding aptamer to selectively recognize the COR target, with one serving as the control. The ratio of the concentration-dependent inhibited photocurrent response (PI1) to the reference signal (PI2) from the control photocathode was employed for the sensitive COR bioassay. The proposed aptasensor revealed a broad linear range toward COR concentration from 0.4 nM to 800 nM, with a detection limit (3S/N) of 0.14 nM. The proposed sensor was successfully applied to real human serum samples, demonstrating promise in detecting disease markers in medical diagnostics.

Electrochemiluminescence Biosensor Based on a Duplex-Specific Nuclease and Dual-Output Toehold-Mediated Strand Displacement Cascade Amplification Strategy for Sensitive Detection of MicroRNA-499.

The timely and accurate diagnosis of acute myocardial infarction (AMI) is of great significance to reduce mortality and morbidity associated with the condition. Herein, we developed an electrochemiluminescence (ECL) biosensor for the detection of the potential AMI biomarker microRNA-499 (miRNA-499), which was based on duplex-specific nuclease-assisted target recycling and dual-output toehold-mediated strand displacement (TMSD). First, miRNA-499 was converted into a large amount of single-stranded DNA through the DSN-assisted target recycling, which was further incubated with the DNA triple-stranded complex (S) to implement TMSD cycles. Thus, the Ru(bpy)32+-labeled signal strands were released and captured by the capture probe on the electrode surface, resulting in an intense ECL signal. Owing to the prominent cascade signal amplification, the constructed biosensor exhibited a good linear response to miRNA-499 within the range of 100 aM-100 pM with a detection limit of 69.99 aM. Furthermore, it demonstrated superior selectivity, stability, and reproducibility. In addition, the biosensor was successfully applied to detect miRNA-499 in real human serum samples, demonstrating its potential for nucleic acid detection in the early diagnosis of diseases.

Sensitive colorimetric detection of glutathione in human serum based on peroxidase-like activity of chitosan-stabilized gold nanoparticles.

Acolorimetric sensor for the rapid and sensitive detection of GSH was developed. The hydrothermal method was utilized to synthesize chitosan-stabilized gold nanoparticles (CS-AuNPs). The synthesized CS-AuNPs were characterized by UV-vis absorption spectroscopy, transmission electron microscopy (TEM), X-ray diffractograms (XRD), and Fourier transform infrared spectroscopy (FTIR). The CS-AuNPs arewell-dispersed and possess aspherical shapewith an average particle size of 10.05 ± 2.26nm in aqueous solution. Theyshow an intrinsic peroxidase-like activity, which could efficiently catalyze the decomposition of H2O2 to produce •OH radicals. These radicals then oxidized 3, 3´, 5, 5´-tetramethylbenzidine (TMB), resulting in the formation of the blue oxidizedproduct oxTMB, observed a visible color change (from colorless to blue), and oxTMB had an obvious absorption peak at 652nm. The presence of GSH could inhibit the peroxidase-like activity of CS-AuNPs, thereby reducing the formation of oxTMB. The solution's blue hue underwent a reduction in absorption intensity. Based on this fact, a novel and sensitive colorimetric sensor for detection of GSH was constructed. Under optimal conditions, the results of detection had an excellent linear relationship between the concentration of GSH and ∆A within the range 0.5 ~ 50.0 × 10-6mol/L. The limit of detection (LOD) for GSH was 2.10 × 10-7mol/L, which was much lower than those in most previous works. Furthermore, for detection in real human serum samples, the recoveries of GSH and the relative standard deviations (RSD) in the serum were in the range 98.40 ~ 103.32% and 1.85 ~ 3.54%, respectively. Thus, this visual colorimetric method has good precision and can be used for GSH detection in practical applications, promising in the fields of bioanalysis and illness diagnostics.

Design and synthesis of a TICT-based red-emissive fluorescent probe for the rapid and selective detection of HSA in human biofluids and live cell imaging.

Here, we report the design and synthesis of a D⋯π⋯A-based fluorescent probe, (E)-4-(4-(dibutylamine)-2-hydroxystyryl)-1-methylquinolin-1-ium (DHMQ), which is nonfluorescent in ∼100% PBS buffer medium due to a twisted intra molecular charge transfer (TICT) phenomenon and it becomes highly fluorescent (∼149 fold) in the presence of human serum albumin (HSA), owing to the restriction of its intramolecular free rotation inside the hydrophobic binding cavity of HSA. The site-selective fluorescence displacement assay and molecular docking studies clearly reveal that DHMQ selectively binds at subdomain IB of HSA. The 3σ/slope method was adopted to determine the limit of detection (LOD) value, which was as low as 2.39 nM in ∼100% PBS medium, indicating its high sensitivity towards HSA. The low dissociation constant value [Kd = (1.066 ± 0.017) μM] suggests a strong complexation between the DHMQ and HSA. Importantly, it has been demonstrated that DHMQ is capable of detecting HSA in real human serum and urine samples and was found to be suitable for live cell imaging of HSA.

Fabrication of Cu-BTC@PW12/GO for multivariate sensing dopamine and acetaminophen as electrochemical sensor

Dopamine (DA) and acetaminophen (AP) are closely associated with many physiological and pathological processes, monitoring their levels precisely is of significance in the early diagnosis of diseases. Herein, a polyoxometalate-based metal-organic framework (POMOF) based on phosphotungstate (Cu-BTC@PW12) was immobilized on graphene oxide (GO) to fabricate Cu-BTC@PW12/GO (CPG) as an electrochemical sensor for the quantification of DA and AP. The spatial confinement effect of copper-based MOF (Cu-BTC) remained the catalytic activity phosphotungstate (PW12) avoiding the aggregation, facilitating electro-catalysis performance for detection of DA and AP. The CPG electrochemical sensor achieved the analysis of DA and AP with the limit of detection (LOD) of 24.8 nM and 62.3 nM, respectively. Furthermore, CPG can be applied for the quantification of DA and AP in real human serum and environmental water samples with satisfied recoveries. Therefore, this work expanded the utilization of POMOF in electrochemical analysis and has promising prospects for the early diagnosis of diseases and environmental treatment.

Polyaniline-based bovine serum albumin imprinted electrochemical sensor for ultra-trace-level detection in clinical and food safety applications

Monitoring bovine serum albumin (BSA) at ultra-low levels is crucial for clinical and food safety applications, as it plays a significant role in identifying various health conditions and potential risks, necessitating fast, trace-level detection of BSA. This study proposes an approach to address these challenges by employing molecularly imprinted polymer (MIP) to develop an ultra-trace-level and cost-effective BSA sensing platform. The MIP electrochemical sensor was developed using polyaniline (PANI) combined with the protein crosslinker glutaraldehyde (GA) to optimize BSA surface imprinting in the MIP. As a result, the sensor achieves a sensitivity of 1.24 μA/log(pg/mL), with a picomolar detectable limit of 2.3 pg/mL (0.035 pM) and a wide detection range from 20 pg/mL to 200,000 pg/mL (0.303 pM to 3030 pM), making it suitable for clinical and food safety applications. Additionally, the study explores the interaction between an acidic surfactant protein eluent (acetic acid with sodium dodecyl sulfate, AcOH-SDS) and BSA vacant sites, enhancing recognition and re-binding. The PANI-based MIP sensor demonstrates initial feasibility and practicality in commercial milk and real human serum, opening avenues for early disease detection and ensuring food safety in BSA-related immune responses.

Nano-immuno-conjugates inspired by hydrophilic perovskite fluorescent spheres and magnetic assisted for detection of hepatitis B surface antigen.

The rampant hepatitis B virus (HBV) seriously endangers human health, and hepatitis B surface antigen (HBsAg) is its early diagnostic marker. Therefore, it is crucial to construct a fast and highly sensitive HBsAg detection method. Based on high-efficiency magnetic separation technology and fluorescent composite material labelling technology, an accurate, fast and sensitive fluorescent immunosensing system for HBsAg detectionwas developed. Immunomagnetic beads constructed from carboxyl-functionalized Fe3O4 nanoparticles (Fe3O4-COOH) with excellent magnetic response performance were used as efficient capture carriers for HBsAg. Immunofluorescence composite microspheres constructed based on ultra-stable polystyrene-coated CsPbBr3 perovskite nanocrystals (CPB@PSAA) with high hydrophilic properties, were excellent fluorescent markers for HBsAg. Using thissensitive sandwich fluorescence sensing system a good linear relationship within the range of 0.2-15ng/mL was established between HBsAg concentrationand fluorescence intensity with alimit of detection (LOD) of 0.05ng/mL. Thesystem obtained satisfactory results when tested on real human serum samples. The magnetic-assisted fluorescence immune-sandwich sensor system has broad application prospects in biomedicine such as rapid and early diagnosis and effective prevention of infectious diseases.

High-Efficiency Degradation of PET Plastics by Glutathione S-Transferase under Mild Conditions.

Plastic pollution is a significant environmental concern globally. Plastics are normally considered chemically inert and resistant to biodegradation. Although many papers have reported enzyme-induced biodegradation of plastics, these studies are primarily limited to enzymes of microbial origin or engineered enzymes. This study reveals that poly(ethylene terephthalate) (PET, ∼6000 Da and 100 kDa) particles and plastic bottle debris (PBD, 24.9 kDa) can be efficiently degraded by a mammal-origin natural phase II metabolic isozyme, glutathione S-transferase (GST), under mild conditions. The degradation efficiency of PET plastics reached 98.9%, with a degradation rate of 2.6 g·L-1·h-1 under ambient or physiological conditions at 1 atm. PET plastics can be degraded by GST with varying environmental or biological factors (i.e., temperature, light irradiation, pH, and presence of humic acid or protein). We suggest a novel mechanism for PET degradation other than hydrolysis, i.e., the mechanism of cleavage and release of PET plastic monomers via nitridation and oxidation. This finding also reveals a novel function of GST, previously thought to only degrade small molecules (<1000 Da). This method has been successfully applied in real human serum samples. Additionally, we have tested and confirmed the ability to degrade PET of a mammal-origin natural digestive enzyme (trypsin) and a human-derived natural metabolic enzyme (CYP450). Overall, our findings provide a potential new route to plastic pollution control and contribute to our understanding of the metabolism and fate of plastics in organisms.

A novel dual-signal output strategy for POCT of CEA based on asmartphone electrochemical aptasensing platform.

A smartphone-based electrochemical aptasensing platform was developed for the point-of-care testing (POCT) of carcinoembryonic antigen (CEA) based on the ferrocene (Fc) and PdPt@PCN-224 dual-signal labeled strategy. The prepared PdPt@PCN-224 nanocomposite showed a strong catalytic property for the reduction of H2O2. Phosphate group-labeled aptamer could capture PdPt@PCN-224 by Zr-O-P bonds to form PdPt@PCN-224-P-Apt. Therefore, a dual signal labeled probe was formed by the hybridization between Fc-DNA and PdPt@PCN-224-P-Apt. The presence of CEA forced PdPt@PCN-224-P-Apt to leave the electrode surface due to the specific affinity, leading to the decrease of the reduction current of H2O2. At the same time, the Fc-DNA strand changed to hairpin structure, which made Fc closer to the electrode and resulted in the increase of the oxidation current of Fc. Thus, CEA can be accurately determined through both signals: the decrease of H2O2 reduction current and the increase of Fc oxidation current, which could avoid the false positive signal. Under the optimal conditions, the prepared aptasensor exhibited a wide linear range from 1pg·mL-1 to 100ng·mL-1 and low detection limits of 0.98pg·mL-1 and 0.27pg·mL-1 with Fc and PdPt@PCN-224 as signal labels, respectively. The aptasensor developed in this study has successfully demonstrated its capability to detect CEA in real human serum samples. These findings suggest that the proposed sensing platform will hold great potential for clinical tumor diagnosis and monitoring.

Fouling-Free electrochemical strategy based on vertically-aligned peptide layer for cardiac troponin I sensitive detection in human serum

BackgroundCardiac troponin I (CTnI) is demonstrated as one of the most promising disease biomarkers for early diagnosing acute myocardial infarction (AMI). To date, electrochemical immunosensors have been extensively studied in the field of cTnI determination. But highly accurate and sensitive cTnI detection by this method is still a challenge due to non-specific adsorption on electrode interfaces in complex human serum. As a result, it is necessary to develop an antifouling electrochemical immunosensor with high sensitivity for the detection of cTnI. ResultsIn this work, an antifouling electrochemical immunosensor was constructed based on vertically-aligned peptide layer consisting of Au nanoparticles (AuNPs) and amphiphilic CEAK16 peptide (CEAK16@AuNPs) for sensitive and accurate detection of cTnI in human serum. The vertically-aligned CEAK16@AuNPs interface provided a stable hydration layer originated from attraction of water molecules by amino acids on the hydrophilic side of the CEAK16, which effectively reduced non-specific adsorption and enhanced electron transfer rate. The cTnI immunosensor possessed great analytical performance with a wide range from 1 fg mL−1 to 1 μg mL−1 and a low detection limit of 0.28 fg mL−1 (S/N = 3). Additionally, the proposed CEAK16@AuNPs sensing interface showed excellent long-term antifouling performance and electrochemical activity that preserved 80 % of the initial signal after 20-days exposure in human serum samples. Consequently, the cTnI immunosensor displayed excellent detection accuracy compared to clinical methods and owned good selectivity, stability and reproducibility. SignificanceThe development of this strategy provides a versatile tool for accurate quantitative cTnI analysis in real human serum, thus helping to achieve early AMI diagnosis effectively and holding the promising potentials for other immunosensor in disease diagnosis.

A highly selective Ru(II) complex-based phosphorescent probe for the sequential sensing Cu2+ and H2S and its applications

A highly selective Ru(II) complex-based phosphorescent probe Ru-Cyclen for the sequential sensing Cu2+ and H2S in pure aqueous medium was synthesized and characterized. Probe Ru-Cyclen exhibited a turn-off phosphorescence response toward Cu2+ by using a complex formation with a 1:1 binding mode, and the resulting complex enabled to specifically detect H2S based on the displacement approach with a turn-on phosphorescence response. Also, Ru-Cyclen possessed high selectivity and sensitivity with a low detection limit of 0.045 μM and 0.44 μM for Cu2+ and H2S respectively, and worked best in the range of pH 3–11. The kinetics response toward Cu2+ and H2S were very fast, completing within 4 min and 10 s, respectively. Additionally, the sensing mechanism was confirmed by fluorescence Job’s plot analysis, 1H NMR titration, EPR, TOF-mass spectrometry and phosphorescence lifetime analysis. Moreover, Ru-Cyclen showed low cell toxicity and successfully detected Cu2+ and exogenously or endogenously generated H2S in living zebrafish. Finally, combining the unique merits of the probe, including excellent water-solubility, a long emission wavelength of 600 nm, large Stoke shift of 150 nm and rapid response, probe Ru-Cyclen was applied in real water samples, human serum and test strips successfully.

Facile Semiconductor p–n Homojunction Nanowires with Strategic p-Type Doping Engineering Combined with Surface Reconstruction for Biosensing Applications

HighlightsA novel photoelectrochemical (PEC) photosensor composed of GaN nanowire-on-Si platform demonstrates record-high responsivity of 247.8 mA W−1 with ultra-stable operation characteristics.Strategic internal and external band structure engineering of semiconductor nanowires promotes efficient PEC reaction via controlling carrier dynamics while preserving nanowires from material degradation.The glucose sensing system is constructed to successfully analyze blood glucose levels in real human serum samples, featuring a high sensitivity of 0.173 µA µM−1 cm−2 and a low detection limit of 0.07 µM.

A new electrochemical biosensor based on graphene oxide for rapid detection of synthetic testosterone as performance-enhancing drugs in athletes

This study showcases the successful development of a hybrid reduced graphene oxide-metal organic framework modified glassy carbon electrode (rGO-MOFs/GCE) electrochemical biosensor for the detection of synthetic testosterone (TST) as a performance-enhancing drug in athletes. The results demonstrate a linear relationship between the voltametric responses and the testosterone concentration, indicating the sensor's effectiveness in measuring TST. Furthermore, the sensor's performance in detecting TST in real human serum samples from athletes was also validated. The sensor's linear range and detection limit are comparable, if not superior, to those of other recently developed electrochemical sensors, positioning it as a promising tool for TST detection. Additionally, the method's selectivity was assessed and found to be unaffected by substances typically present in biological fluids and food samples, further affirming the sensor's reliability. The application of the rGO/MOF/GCE sensor to detecting and quantifying TST in actual human serum samples yielded favorable results. The synergistic effects of rGO and MOF, which improve the electrical conductivity and biocompatibility of MOF and the porosity and catalytic activity of rGO, are responsible for the sensor's enhanced performance in terms of sensitivity, selectivity, stability, and response time. These findings underscore the potential of the rGO/MOF/GCE sensor platform for various biomedical applications.

Bis-tridentate Iridium(III) Complex with the N-Heterocyclic Carbene Ligand as a Novel Efficient Electrochemiluminescence Emitter for the Sandwich Immunoassay of the HHV-6A Virus.

Human herpesvirus type 6A (HHV-6A) can cause a series of immune and neurological diseases, and the establishment of a sensitive biosensor for the rapid detection of HHV-6A is of great significance for public health and safety. Herein, a bis-tridentate iridium complex (BisLT-Ir-NHC) comprising the N-heterocyclic carbene (NHC) ligand as a novel kind of efficient ECL luminophore has been unprecedently reported. Based on its excellent ECL properties, a new sensitive ECL-based sandwich immunosensor to detect the HHV-6A virus was successfully constructed by encapsulating BisLT-Ir-NHC into silica nanoparticles and embellishing ECL sensing interface with MXene@Au-CS. Notably, the immunosensor illustrated in this work not only had a wide linear range of 102 to 107 cps/μL but also showed outstanding recoveries (98.33-105.11%) in real human serum with an RSD of 0.85-3.56%. Undoubtedly, these results demonstrated the significant potential of the bis-tridentate iridium(III) complex containing an NHC ligand in developing ECL-based sensitive analytical methods for virus detection and exploring novel kinds of efficient iridium-based ECL luminophores in the future.