Influence of the Gold Nanoparticle Size on the Colorimetric Detection of Histamine.

Histamine is a well-known biogenic amine (BA) that is often associated with allergic reactions and is a significant cause of foodborne illnesses resulting from the consumption of spoiled food. Detecting histamine is essential for maintaining food safety standards and preserving the quality. In this work, we developed a simple, low-cost, and rapid colorimetric method for detecting histamine. Gold nanoparticles (AuNPs) of different sizes (16, 25, and 40 nm) were synthesized by using the citrate reduction method. The particle size was controlled by adjusting the precursor molar ratio (MR), with smaller ratios leading to larger particles and a red-shift in the surface plasmon resonance (SPR) peak (520, 524, and 528 nm). The nanoparticles were allowed to interact with increasing concentrations of histamine (ranging from 1 to 100 ppm), and the changes in the absorbance spectra and color of the solution were monitored. AuNP aggregation was induced by interaction with histamine through amino and imidazole groups that will coordinate with the AuNP's surface via electrostatic and hydrogen-bonding interactions, causing the solution to turn blue from red. The size variations of AuNPs significantly affected the colorimetric response to histamine. Among the varied sizes, 25 nm AuNPs exhibited the lowest detection limit of 0.72 μM and a linear detection range of 1-10 ppm. Notably, this sensor offered rapid detection (under 1 min) and a remarkable selectivity toward histamine analyte, highlighting its potential for practical applications.