Green Synthesis Gold and Silver Nanoparticles and Their Potential as Glucose Monitoring on Paper Analytical Device

Controlling the glucose content in the body is crucial to preventing serious diseases. The American Diabetes Association sets the maximum limit for glucose levels in a person's body at 10 mmol/L. In a previous study, the Analytical Paper Device (μPAD) was invented to make glucose detection easy, cheap, and efficient. Unfortunately, the materials used for sample quantification are still not environmentally friendly, and additional enzymes are required. Therefore, in this study, we prepared AgNPs and AuNPs using the green synthesis method by adding a red dragon fruit peel extract mixture in the experimental process. To ensure the formation of AuNPs and AgNPs was successful, we used a laser to observe a clear strike line, indicating the nanoparticles' presence in the dispersion. The absorbance peaks were observed using UV-Vis spectrometry; the formation of AgNPs was detected within the range of 400 nm, while AuNPs were formed in the 500-600 nm range. We also measured the particle size using PSA. Immobilization is done by dripping the sample on the μPAD and observing its color change after addition. The image analysis was performed using a simple smartphone application, Image-J. Thus, this study set out to develop synthesizing nanoparticles for glucose detection that are naturally degradable and eco-compatible.