Recent Advances in Colorimetric Sensors Based on Gold Nanoparticles for Pathogen Detection

Abstract

Infectious pathogens cause severe threats to public health due to their frightening infectivity and lethal capacity. Rapid and accurate detection of pathogens is of great significance for preventing their infection. Gold nanoparticles have drawn considerable attention in colorimetric biosensing during the past decades due to their unique physicochemical properties. Colorimetric diagnosis platforms based on functionalized AuNPs are emerging as a promising pathogen-analysis technique with the merits of high sensitivity, low-cost, and easy operation. This review summarizes the recent development in this field. We first introduce the significance of detecting pathogens and the characteristics of gold nanoparticles. Four types of colorimetric strategies, including the application of indirect target-mediated aggregation, chromogenic substrate-mediated catalytic activity, point-of-care testing (POCT) devices, and machine learning-assisted colorimetric sensor arrays, are systematically introduced. In particular, three biomolecule-functionalized AuNP-based colorimetric sensors are described in detail. Finally, we conclude by presenting our subjective views on the present challenges and some appropriate suggestions for future research directions of colorimetric sensors.

Biosensor Design for the Detection of Circulating Tumor Cells Using the Quartz Crystal Resonator Technique

“…At a specific excitation frequency, for time-harmonic waves, the standing wave equation can be described as follows [ 25 ]: where k 2 is the shear horizontal acoustic wave number in the x 2 direction, and ω is the angular excitation frequency ( ω = 2 πf ). The acoustic wave equation can be simplified as follows [ 20 , 21 ]: where C ij is the elastic stiffness constant, is the wavenumber of driving frequency, and v is the velocity for the propagation of the shear wave given by ( C 66 /ρ q ) ½ . represents the acoustically stiffened elastic constant.…”

“…Colorimetric biosensing functions are based on changes in the mode of nanoparticles, which lead to changes in color. This is based on the fact that GNPs can exist in both aggregate and non-aggregate forms in the solution [ 20 , 21 ]. Meanwhile, refractive index changes at the nanoparticle surface are detected by LSPR-based biosensing measurements [ 22 ].…”

Nanomaterial interfaces designed with different biorecognition elements for biosensing of key foodborne pathogens

“…The shape and size of AuNPs need to be optimized to improve sensitivity of biosensor. Reducing the size of AuNPs results in an increase in the specific surface area of the particles, which in turn enhances their peroxidase‐mimicking property (Yang et al., 2023). Moreover, the different morphologies exhibited by gold nanoparticles cause differences in their optical, catalytic, and electronic behavior (Holzinger et al., 2014).…”

“…In addition, the catalytic activity of AuNPs can be inhibited by interfering substances such as proteins, carbohydrates, and ions. To enable the detection of pathogens in real samples, it is necessary to further enhance the anti‐interference capacity of the sensing system (Yang et al., 2023). Achieving stability in AuNP aggregates is vital for obtaining accurate results as the color of AuNP aggregates can fade over time (Hua et al., 2021).…”

Applications of nanomaterials as treatments and diagnostic biosensors in microbial infections

“…For example, scattered spherical AuNPs appear burgundy in solution, while clustered AuNPs change color from red to blue with increasing diameter, so this characteristic is widely utilized to detect analytes. 72 NPs have an enzyme-like activity that can alter colorimetric reactions by catalyzing chromogenic substrates, such as TMB, and some pH indicators. 73 In addition, effectively capturing and immobilizing bacteria are essential for improving the selectivity and specificity of bacterial detection.…”