A flexible self-supported electrochemical sensor Co-NC/PS@CC for real-time detection of cell-released H2O2.

BACKGROUND: Hydrogen peroxide (H2O2) is an important reactive oxygen species (ROS) molecule involved in cell metabolism regulation, transcriptional regulation, and cytoskeleton remodeling. Real-time monitoring of H2O2 levels in live cells is of great significance for disease prevention and diagnosis. RESULTS: We utilized carbon cloth (CC) as the substrate material and employed a single-atom catalysis strategy to prepare a flexible self-supported sensing platform for the real-time detection of H2O2 secreted by live cells. By adjusting the coordination structure of single-atom sites through P and S doping, a cobalt single-atom nanoenzyme Co-NC/PS with excellent peroxidase-like activity was obtained. Furthermore, we explored the enzyme kinetics and possible catalytic mechanism of Co-NC/PS. Due to the excellent flexibility, high conductivity, strong adsorption performance of carbon cloth, and the introduction of non-metallic atom-doped active sites, the developed Co-NC/PS@CC exhibited ideal sensing performance. Experimental results showed that the linear response range for H2O2 was 1-17328 µM, with a detection limit (LOD) of 0.1687 µM. Additionally, the sensor demonstrated good reproducibility, repeatability, anti-interference, and stability. SIGNIFICANCE: The Co-NC/PS@CC prepared in this study has been successfully applied for detecting H2O2 secreted by MCF-7 live cells, expanding the application of single-atom nanoenzymes in live cell biosensing, with significant implications for health monitoring and clinical diagnostics.

Synergistic enhancement of wearable biosensor through Pt single-atom catalyst for sweat analysis.

Real-time monitoring of biological markers in sweat is a valuable tool for health assessment. In this study, we have developed an innovative wearable biosensor for precise analysis of glucose in sweat during physical activities. The sensor is based on a single-atom catalyst of platinum (Pt) uniformly dispersed on tricobalt tetroxide (Co3O4) nanorods and reduced graphene oxide (rGO), featuring a unique three-dimensional nanostructure and excellent glucose electrocatalytic performance with a wide detection range of 1-800 µM. Additionally, density functional theory calculations have revealed the synergetic role of Pt active sites in the Pt single-atom catalyst (Co3O4/rGO/Pt) in glucose adsorption and electron transfer, thereby enhancing sensor performance. To enable application in wearable devices, we designed an S-shaped microfluidic chip and a point-of-care testing (POCT) device, both of which were validated for effectiveness through actual use by volunteers. This research provides valuable insights and innovative approaches for analyzing sweat glucose using wearable devices, contributing to the advancement of personalized healthcare.

A wearable flexible electrochemical biosensor with CuNi-MOF@rGO modification for simultaneous detection of uric acid and dopamine in sweat.

BACKGROUND: In health assessment and personalized medical services, accurate detection of biological markers such as dopamine (DA) and uric acid (UA) in sweat is crucial for providing valuable physiological information. However, there are challenges in detecting sweat biomarkers due to their low concentrations, variations in sweat yield among individuals, and the need for efficient sweat collection. RESULTS: We synthesized CuNi-MOF@rGO as a high-activity electrocatalyst and investigated its feasibility and electrochemical mechanism for simultaneously detecting low-concentration biomarkers UA and DA. Interaction between the non-coordinating carboxylate group and the sample produces effective separation signals for DA and UA. The wearable biomimetic biosensor has a wide linear range of 1-500 µM, with a detection limit of 9.41 µM and sensitivity of 0.019 µA µM-1 cm-2 for DA, and 10-1000 µM, with a detection limit of 9.09 µM and sensitivity of 0.026 µA µM-1 cm-2 for UA. Thus, our sensor performs excellently in detecting low-concentration biomarkers. To improve sweat collection, we designed a microfluidic-controlled device with hydrophilic modification in the microchannel. Experimental results show optimal ink flow at 2% concentration. Overall, we developed an innovative and highly active electrocatalyst, successfully enabling simultaneous detection of low-concentration biomarkers UA and DA. SIGNIFICANCE: This study provides a strategy for sweat analysis and health monitoring. Moreover, the sensor also showed good performance in detecting real sweat samples. This study has shown great potential in future advances in sweat analysis and health monitoring.

Fe Single-Atom Nanozyme-Modified Wearable Hydrogel Patch for Precise Analysis of Uric Acid at Rest.

Resting sweat analysis could provide unique insight into the metabolic levels of physiological and pathological states. However, the low secretion rate of resting sweat and the low concentration of metabolic molecules pose challenges for the development of noninvasive wearable sensors. Here, we demonstrated a wearable patch for the precise analysis of uric acid at rest. Fe single-atom nanozymes (FeSAs) with excellent electrocatalytic activity were used to develop a sensor for selective catalysis of uric acid (UA, 1-425 µM), and the catalytic mechanism of UA was later explored by density functional theory. In addition, polyaniline was integrated into the wearable patch for pH detection; thus, accurate analysis of sweat UA molecules can be achieved by pH calibration. Then, we explored the possibility of collecting resting sweat with different ratios of agarose hydrogels to reduce the sweat accumulation time. Finally, the possibility of a wearable patch for accurate UA detection in volunteer sweat samples was experimentally verified. We believe that our work provides novel insights and ideas for the analysis of resting sweat using wearable devices, further driving advancements in the field of personalized medicine.

Association of serum ADAMTS7 levels and genetic variant rs1994016 with acute coronary syndrome in a Chinese population: A case control study.

BACKGROUND AND AIMS: Acute coronary syndrome (ACS) is commonly caused by rupture or erosion of coronary atherosclerotic plaques and secondary thrombus formation. Metalloproteinase ADAMTS7 was found to play an important role in atherogenesis. This study aimed to explore the association of serum ADAMTS7 levels and rs1994016 polymorphism at ADAMTS7 locus with ACS in a Chinese population. METHODS: 1881 patients who underwent coronary angiography were consecutively recruited. Among them, 426 patients were matched for case-controlled analysis. Serum ADAMTS7 levels were determined through enzyme-linked immunosorbent assay (ELISA) and rs1994016 polymorphism was detected by polymerase chain reaction (PCR). RESULTS: Serum ADAMTS7 levels in patients with unstable angina pectoris were much higher than in non-atherosclerotic patients, however, no difference was found among non-atherosclerotic patients, the coronary atherosclerosis subgroup and stable angina pectoris subgroup. A higher serum ADAMTS7 level was found in the ACS group than in the non-ACS group (0.61 ±â€¯0.04 vs. 0.47 ±â€¯0.02 ng/mL, p = 0.002) and serum ADAMTS7 level was found to be an independent risk factor for ACS after adjusting for major confounding factors (OR:2.81, 95% CI:1.33-5.93, p = 0.007). ADAMTS7 rs1994016 CT/TT polymorphism was negatively associated with the risk of ACS (OR:0.40, 95% CI:0.22-0.71, p = 0.002). Meanwhile, crossover analysis revealed that in CT/TT homozygotes, ACS risk was reduced nearly 80% in patients with serum ADAMTS7 levels <0.594 ng/mL (Interaction p = 0.002). CONCLUSIONS: Serum level of ADAMTS7 was positively associated and rs1994016 CT/TT genotype was negatively associated with the risk of ACS. Patients with lower serum ADAMTS7 level and rs1994016 CT/TT genotype are less likely to suffer from ACS in a Chinese population.