Implementation of a Low-Cost Automated LED Photometer for Enzymatic Reaction Detection to Teach Basic Bioelectronics Technologies in Vocational High Schools

This study proposes a home-assembled, low-cost blue light-emitting diode (LED) photometer that uses simple and low-cost hardware and software, costing about US $150. This 425-nm wavelength photometer is controlled by an 89C51 microcontroller chip. Glucose concentration detection experiments involving enzyme coupling reactions were carried out to verify the performance of the proposed system. Measurement errors for the system were between 3% and 4%, which can be further improved to less than 2%. The proposed LED photometer can be used by students in electronics classes to conduct biotechnological tests as part of their electrical and electronics vocational high school education. This can help them to explore the basic applications of biosensors and enhance their professional abilities in executing fundamental bioelectronics processes. Pretest and post-test assessments of students' knowledge of bioelectronics were conducted to determine the efficacy of the proposed system in enhancing students' knowledge. The LED photometer can be modified to test various samples in biochemistry and analytical chemistry, and it can also be applied to various fields such as electronics, chemical engineering, and biochemistry.