A sensitive resonance Rayleigh scattering sensor for dopamine in urine using upconversion nanoparticles

Abstract

A highly sensitive resonance light scattering method for detecting dopamine in urine was developed by using a novel probe based on lanthanide-doped upconversion nanoparticles (UCNPs) linked to dopamine–quinone (DQ) by hydrogen bonding and electrostatic interactions. Adding dopamine to a solution containing UCNPs decreases their size and the intensity of their resonance light scattering signals. Based on the decrease, dopamine can be determined in Tris–HCl buffer and in urine samples spiked with analyte concentrations over the range 0–300 μM with a limit of detection of 1.62 μM. As-prepared UD can thus provide an effective platform for biosensor development, drug discovery, and rapid diagnosis of Parkinson's and Alzheimer's disease, among other medical conditions.