Dual Reaction-Based Multimodal Assay for Dopamine with High Sensitivity and Selectivity Using Functionalized Gold...

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Biomedical Diagnostics

Background:

• Dopamine is a crucial neurotransmitter implicated in various physiological and pathological processes.
• Accurate and sensitive detection of dopamine is essential for clinical diagnosis and research.
• Existing detection methods may lack sensitivity, selectivity, or multimodal capabilities.

Purpose of the Study:

• To develop a simple, highly sensitive, and selective multimodal assay for dopamine detection.
• To utilize functionalized gold nanoparticles for simultaneous colorimetric and fluorescent signal generation.
• To validate the assay's performance in complex biological matrices like human urine.

Main Methods:

• Fabrication of fluorescein modified gold nanoparticles (FB-AuNPs) and Nile blue modified gold nanoparticles (NsNHS-AuNPs).
• Development of a dual chemical reaction mechanism enabling multimodal signal output.
• Quantitative analysis of dopamine using absorbance and fluorescence spectroscopy.
• Assay validation using human urine samples.

Main Results:

• The assay demonstrated linear responses to dopamine in the nanomolar range (5-100 nM).
• Achieved low detection limits of 1.2 nM for absorbance and 2.9 nM for fluorescence (S/N = 3).
• Successfully applied the assay to human urine samples with high reliability.

Conclusions:

• A novel dual chemical reaction-based multimodal assay for dopamine was successfully developed.
• The assay offers high sensitivity, selectivity, and dual-channel detection (colorimetric and fluorescence).
• The method shows significant potential for reliable and applicable diagnostic purposes, particularly in analyzing human urine.