Small Size Effect and Concentration Response of Gold Nanoparticles in Electrochemiluminescence Reaction

Abstract

Recent reports have used gold nanoparticles (AuNPs) as a co‐reactant for the electrochemiluminescence (ECL) reaction of ruthenium complex. However, understanding the size effect of AuNPs on ECL reaction is very meaningful to explore its unknowns and develop its applications at the molecular level. In this paper, we examined the behavior of various small‐size AuNPs in ECL reaction, focusing on changes in ECL caused by AuNPs size and reasons for this change. Although the luminescence spectra and excitation potential have hardly changed in ECL reaction, the difference of ECL intensities induced by different sizes AuNPs is very obviously. Our experimental results revealed disparate behaviors depending on AuNPs size: the small‐sized AuNPs can lead to stronger ECL, and ECL intensities increase as the addition of AuNPs concentration in the wider range. This small size effect is related to an intermediate process of charge‐discharge in electric double layer formed by adsorbing ruthenium complex with AuNPs, and the surface and quantum size effect of AuNPs may affect this intermediate process. More importantly, AuNPs can act as a marker, has the same small size effect and concentration response, and bring about a promising platform for biochemical analysis.

A novel electrochemiluminescence biosensing system using photonic crystal as luminescence enhanced substrates for the ultrasensitive detection of food-borne harmful substances

“…Under this circumstance, the ECL signal of CdS quantum dots recovers and the off-on detection strategy of Aflatoxin B1 was constructed [36]. A linear relationship between ECL signal strength and Aflatoxin B1 concentration can be established [37]. To determine Aflatoxin B1 concentration in crunched peanut samples [38], this research showed an ultrasensitive ECL biosensor for detecting Aflatoxin B1 which offers a new venue for monitoring the Aflatoxin B1 concentration in food.…”