Multifunctional sodium alginate fabric based on reduced graphene oxide and polypyrrole for wearable closed-loop point-of-care application

Sodium alginate (SA) fabrics decorated with reduced graphene oxide (rGO) and polypyrrole (PPy) serving as multifunctional materials are prepared by thermal-press reduction and in-situ polymerization. The superior conductivity (0.17 k Omega.sq(-1)) of SA/rGO/PPy composite fabric is optimized through L-9(3(4)) orthogonal experimental design. Microstructures of the resultant SA/rGO/PPy composite fabric are investigated by field emission-scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction measurement, respectively. It is found that SA/rGO/PPy composite fabric possesses not only excellent thermal stability but also mechanical durability. The results of NH3 gas experiments indicate that SA/rGO/PPy composite fabric exhibits reliable linearity of concentration (2-16 ppm) dependency, unique repeatability, a high sensing response (10.7%) at low detection limit of 2 ppm and admirable selectivity. Moreover, SA/rGO/PPy composite fabric acting as a heater can reach to approximately 40-90 degrees C at low voltage of 3 V to 9 V. Hence, the optimum SA/rGO/PPy composite fabric is supposed to be used as ultrasensitive NH3 gas sensor and wearable heater for nephropathy diagnosis purpose and thermo-responsive drug deliver in point-of-care (POC) application to develop a closed-loop treatment.

Automated summary

SA/rGO/PPy composite fabric, prepared by thermal-press reduction and in-situ polymerization, exhibits superior conductivity, thermal stability, and mechanical durability. The fabric shows reliable linearity of concentration, high sensing response, and good selectivity in NH3 gas experiments. Additionally, it can act as a heater reaching high temperatures at low voltages.