Development of LED Based Enzyme-Linked Immunosorbent Assay Reader

Abstract

Enzyme-linked immunosorbent assay or better known as ELISA is a method commonly used for detecting antigen / antibody in the blood sample taken from the patient. The presence of antigen / antibody is detected for diagnosing viral infection such as Hepatitis, HIV or malaria. Although this method is gold standard for viral detection, this method is rarely use due to additional equipment need for the test. The ELISA reader that being designed use wavelength of 450 nm for the measurement and measured the optical density using 8 silicone photodiode. To guarantee that every photodiode have the same wavelength, the light source are split into 8 individual channel using fiber optic. Verification method is done by comparing the measurement result from the ELISA that been designed and compare it with commercial ELISA reader. The result show that ELISA reader that been designed have measurement range from 0.03 OD to 1.62 OD with correlation coefficient (R2) of 0.962. The error from the ELISA reader that been designed is $0.091 \pm 0.096$ OD