Recent developments in colorimetric immunoassays using nanozymes and plasmonic nanoparticles

Abstract

Enzyme-linked immunosorbent assay (ELISA) is a popular detection technique for the screening and diagnosis of diseases. The sensitivity of ELISA can be increased by the incorporation of nanoparticles. Through this article, we discuss the utilization of nanoparticles in ELISA. Nanoparticles possess an intrinsic biological peroxidase-like activity which allows it to act as an enzyme mimic for the development of an improved analysis method. Different nanoparticles (gold nanoparticles, silver nanoparticles, etc.) carry different peroxidase-mimic characteristics. Besides this, nanoparticles can also perform as a colorimetric substrate in ELISA where it gives a more prominent color change compared to the commonly used colorimetric substrate TMB. This article also focuses on the mechanisms behind this color change including aggregation, in situ nanoparticle growth, seeding, and etching.

Gold Nanozymes: From Concept to Biomedical Applications

“…Since then, the nanozyme activity of different families of nanomaterials has been reviewed. Some of these studies are more generic [80][81][82][83][84], while some others are specific for gold nanomaterials [14], metal-organic frameworks (MOFs) [85,86] or metal-oxide nanomaterials (MONMs) [87]. Although similar reviews have been published elsewhere, e.g., covering either the factors controlling the activity of gold nanozymes [88] or their potential biosensing and therapeutic applications [89], this review is presented as a comprehensive analysis intending to link both sections, from the fabrication of gold nanozymes, their catalytic mechanisms, potential applications and obstacles in the biomedical field.…”

Colorimetric assay based on iron(iii) ions triggering the aggregation of a poly(tannic acid) coated Au nanocomposite for carbonic anhydrase II detection

“…Compared with the various detection methods relying on professional and sophisticated analysis instrumentation, [3][4][5][6][7] the colorimetric assays, which is easy to monitor with the naked eye, are constantly improved for satisfying home-testing or on-site detection. [8][9][10][11][12] For this assay, numerous types of sensors such as Au nanoparticles, [13][14][15][16] quantum dots 17,18 and silver nanoparticles 19,20 have been explored.…”

Multicolorimetric ELISA biosensors on a paper/polymer hybrid analytical device for visual point-of-care detection of infection diseases

“…The multicolorimetric ELISA method can be a promising solution that can eliminate the use of these expensive and bulky instruments and allow it to be portable and cost-effective. Particularly, multicolorimetric sensing based on noble metal nanomaterial such as AuNRs [19] has attracted great interest owing to its advantages of visual color readout, simplicity, and robust enzymatic properties of nanomaterials, and those methods have been applied to detect various biomolecules and pathogens, such as pesticides, glucose, and Listeria monocytogenes [20][21][22][23]. For instance, a multicolorimetric sensor was developed for the detection of a toxic organophosphorus pesticide, omethoate, in a centrifuge tube based on the inhibition of the enzyme-induced metallization of AuNRs [20].…”