In-situ synthesized silver nanoparticles on distance-based microfluidic paper based analytical devices for non-enzymatic glucose detection in artificial urine

Diabetes mellitus, a prevalent metabolic disorder characterized by insulin deficiency and elevated blood glucose levels, is often associated with unhealthy lifestyles, underscoring the need for accessible glucose monitoring. In this work, a non-enzymatic approach for glucose detection in artificial urine was developed using distance-based microfluidic paper-based analytical devices (d-μPADs) with in-situ synthesized silver nanoparticles (AgNPs) as the detection mechanism. The d-μPADs were fabricated from Whatman No. 1 chromatographic paper, printed using a solid ink printer to create hydrophilic and hydrophobic regions. AgNPs were formed through the reduction of AgNO₃ by glucose in the presence of NaOH, with starch serving as a stabilizer. The optimized experimental parameters were established as 20 mM AgNO₃, 8 M NaOH, single reagent immobilization, and a 20-minute reaction time. Under these conditions, the d-μPADs exhibited good linearity (5–100 mg/dL) with a correlation coefficient of 0.9253, high precision (%RSD = 1.88%), high accuracy (82.55% - 98.99%), and good sensitivity (limit of detection: 4.86 mg/dL). These findings suggest that d-μPADs incorporating AgNPs offer a low-cost, accessible solution for glucose monitoring, with potential applications in point-of-care diagnostics.