A highly selective and stable cationic polyelectrolyte encapsulated black phosphorene based impedimetric immunosensor for Interleukin-6 biomarker detection.

Due to the insufficiency of binding sites for the immobilized recognition biomolecules on the immunosensing platform, cancer detection becomes challenging. Whereas, the degradation of black phosphorene (BP) in the presence of the environmental factors becomes a concerning issue for use in electrochemical sensing. In this study, BP is successfully encapsulated by polyallylamine (PAMI) to increase its stability as well as to enhance its electrochemical performance. The successful encapsulation of BP is ensured through X-ray Photoelectron spectroscopy and Raman spectroscopy, whereas the stability of black phosphorus is ensured by Zeta potential measurements and cyclic voltammetry tests. The developed BP-PAMI composite showed high stability in the ambient environment and exhibited improved electrochemical performances. The impedimetric immunosensor was developed on a BP-PAMI modified laser burned graphene (LBG) to detect interleukin-6 biomarkers using electrochemical impedance spectroscopy (EIS). Under the optimized parameters, the fabricated immunosensor demonstrated a wide linear range of 0.003-75 ng/mL, limit of detection (LOD) of 1 pg/mL. Based on the experimental analysis, the developed sensing strategy can be employed as an easy, disposable, cost-effective and highly selective point-of-care cancer detection. In addition, the developed technique can be applied broadly for detecting other biomarkers after treating with suitable biomolecules.

Highly flexible and conductive poly (3, 4-ethylene dioxythiophene)-poly (styrene sulfonate) anchored 3-dimensional porous graphene network-based electrochemical biosensor for glucose and pH detection in human perspiration.

The patterned LIG flakes are generally not interconnected due to the line gap of the laser ray, leading to lower uniform conductivity and fragile graphene. Thus, the fabrication of a highly conductive and mechanically robust LIG-based biosensing platform remains challenging. In this study, the fabrication of a flexible electrochemical biosensor is reported based on poly (3, 4-ethylene dioxythiophene)-poly (styrene sulfonate) (PEDOT:PSS) modified 3-dimensional (3D) stable porous laser-induced graphene (LIG) for the detection of glucose and pH. PEDOT:PSS was spray-coated on the LIG to improve electrode robustness and deliver uniform electrical conductivity. The as-prepared PEDOT:PSS modified LIG (PP/LIG) was characterized using field-emission scanning electron microscopy (FESEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). Platinum and palladium nanoparticles (Pt@Pd) were successfully electrodeposited on PP/LIG, markedly enhancing the electrocatalytic activity for glucose detection. The fabricated biosensor exhibited an excellent amperometric response to glucose with a wide linear range of 10 µM - 9.2 mM, a high sensitivity of 247.3 µAmM-1cm-2, and a low detection limit (LOD) of 3 µM, with high selectivity. In addition, the pH sensor was functionalized by the polyaniline (PANI) on PP/LIG, and it also exhibited excellent potentiometric response with a high sensitivity of 75.06 mV/pH in the linear range of pH 4 - 7. Ultimately, the feasibility of the biosensor was confirmed by the analysis of human perspiration collected during physical exercise. This approach validates the utility of the novel fabrication procedure, and the potential of the LIG-conductive polymer composite for biosensing applications.

Association between colony-stimulating factor 1 receptor gene polymorphisms and asthma risk.

Colony-stimulating factor 1 receptor (CSF1R) is expressed in monocytes/macrophages and dendritic cells. These cells play important roles in the innate immune response, which is regarded as an important aspect of asthma development. Genetic alterations in the CSF1R gene may contribute to the development of asthma. We investigated whether CSF1R gene polymorphisms were associated with the risk of asthma. Through direct DNA sequencing of the CSF1R gene, we identified 28 single nucleotide polymorphisms (SNPs) and genotyped them in 303 normal controls and 498 asthmatic patients. Expression of CSF1R protein and mRNA were measured on CD14-positive monocytes and neutrophils in peripheral blood of asthmatic patients using flow cytometry and real-time PCR. Among the 28 polymorphisms, two intronic polymorphism (+20511C>T and +22693T>C) were associated with the risk of asthma by logistic regression analysis. The frequencies of the minor allele at CSF1R +20511C>T and +22693T>C were higher in asthmatic subjects than in normal controls (4.6 vs. 7.7%, p = 0.001 in co-dominant and dominant models; 16.4 vs. 25.8%, p = 0.0006 in a recessive model). CSF1R mRNA levels in neutrophils of the asthmatic patients having the +22693CC allele were higher than in those having the +22693TT allele (p = 0.026). Asthmatic patients with the +22693CC allele also showed significantly higher CSF1R expression on CD14-positive monocytes and neutrophils than did those with the +22693TT allele (p = 0.045 and p = 0.044). The +20511C>T SNP had no association with CSF1R mRNA or protein expression. In conclusion, the minor allele at CSF1R +22693T>C may have a susceptibility effect in the development of asthma, via increased CSF1R protein and mRNA expression in inflammatory cells.