Silver Nanocluster Based Surface Enhanced Raman Scattering Adenine Sensor with a Very Low Detection Concentration Limit

Abstract

Adenine molecules are important for biological and medical research and applications The detection of low concentration of adenine molecules is thus desirable This paper reports a silver-based surface enhanced Raman scattering (SERS) sensor capable of detecting 10-12 M adenine molecules in water Closely spaced silver nanoparticles are grown by chemical plating on discrete copper bumps located in etched holes in a silicon substrate The copper bumps and silicon substrate are covered by rapid thermal CVD graphene with a high-density of domain boundaries and defects exhibiting a strong D-band besides a G-band and a 2-D band in the Raman spectrum The graphene serves as a mask to only allow chemical plating of silver to occur on copper surface which is not covered by graphene or through defects of graphene covering copper The pH value of adenine water solution is altered to optimize interactions and adsorption of adenine with the sensor surfaces The lowest detection limit of 10-12 M adenine in pH9 water solution is achieved

Date of Award	2020
Original language	English
Supervisor	Yon-Hua Tzeng (Supervisor)