Optical Biosensor for Glucose Detection Based on the Green Synthesis of Silicon Nanoparticles using Ocimum Basilicum Purpurascens Extract

Abstract

In the present research, we outline green synthesis of silicon nanoparticles (SiNPs) using a aqueous extract of Ocimum basilicum purpurascens, known as purple basil, and also for the utilization as a non-enzymatic glucose detection biosensor. Using the photoluminescence characteristics of SiNPs, glucose was detected. SiNPs of about 2.01 nm by dynamic light scattering (DLS) and with the use of atomic force microscopy (AFM) we could estimate values below at 2 nm, showing a photoluminescent peak at 441 nm were synthesized by this method. Optical characterization of the biosensor using the interaction of SiNPs in solution with different glucose concentrations resulted in a shift in the emission of the solution. A silicon nanoparticle and a photodetector constitute the optical biosensor. It needs to be noted that the transduction is indirectly obtained by the response of luminescent silicon nanoparticles. The electrical characterization of the photodetector revealed that the resistance changed from 15k\(\Omega \) to 68k\(\Omega \), and the voltage varied from about 1.4V to 0.4V. 84.5\(\upmu \) A was the current in the photodetector for the pure nanoparticles. In contrast, after glucose was introduced to the nanoparticles, the value dropped to 6.12\(\upmu \) A. There is a one-order-of-magnitude difference between the two readings. These findings illustrate the effectiveness of SiNPs synthesized with natural extracts as an excellent alternative to glucose monitoring with advantages such as enhanced stability, sensitivity, and biocompatibility.