Improved Series Photodetector Frequency Circuit System for U1392-Hex Fluorescence Detection in a Deoxyribonucleic Acid (DNA) Probe

Abstract

A 48 MHz series photodetector frequency circuit system with good sensitivity was developed for Hex fluorescence detection of a deoxyribonucleic acid (DNA) probe U1392. According to derived theory of series photodetector frequency circuit system, the circuit parameters such as the capacitance of the photodetector, Cp, and A = (tan θ) can be applied to improve the frequency sensitivity. In this research Cp was selected to improve the frequency sensitivity. On the basis of A adjustment, the capacitance parameter, Cm, of 48 MHz series photodetector frequency circuit system was adjusted to improve the frequency sensitivity for detection of fluorescence dye concentration. In the optimal conditions of capacitance of photodetector and capacitance match, the detection limit of U1392-Hex fluorescence dye concentration 3.3 pmol/l can be measured by the 48 MHzsensor system. Moreover, the frequency method showed that the detection limit of U1392-Hex fluorescence dye concentration was lower than the conventional fluorescence technique by two to three orders of magnitude.