Optical detection of phenolic compounds based on the surface plasmon resonance band of Au nanoparticles

Paper-based assay of antioxidant activity using analyte-mediated on-paper nucleation of gold nanoparticles as colorimetric probes

“…Beyond gold ions, other components such as citrate, CTAB (as a stability and growth regulator of AuNPs) and pH play a crucial role in the formation and growth of AuNPs [11,12,14]. Results of this variance analysis verified that all of the components affect the signal intensity.…”

“…On the basis of the calibration plots of Table 1, the Au paperbased sensor apparently offers equivalent or slightly improved sensitivity compared to that observed from the direct use of NPs in solution [11][12][13][14][15]27]. However, it should be bear in mind that at low concentration levels the sensitivity of the assay strongly depends upon the ability of the detectors (e.g.…”

“…These assays either exploit the ability of antioxidants to reduce noble metals towards the formation of the respective nanoparticles (e.g. AuCl 4 À to AuNPs, Ag + to AgNPs) [11][12][13][14] or use antioxidants as reducing agents in the seed-mediated growth technique, where small NP seeds serve as nucleation centers to the growth and further enlargement of nanoparticles [15,16]. Since the absorbance of the colloidal NP suspensions depends on the properties of the surface resonance plasmon bands, intense colorimetric and chromatic transitions are observed which are used as a measure of antioxidant activity.…”

Nanotechnological Methods of Antioxidant Characterization

“…The optical determination of hydrogen peroxide scavenging activity with the use of NP-based assays differs in principle from chemical reduction-based assays, because neither seeding nor growth of Au/Ag-NPs by antioxidants (acting as reductants) is targeted, and an alternative strategy relying on the inhibition of H 2 O 2 -induced growth of gold nanoshells (GNSs) by hydrogen peroxide scavenging compounds is adapted (64). H 2 O 2 enlarged the AuNPs on the surface of GNSs precursor nanocomposites (SiO 2 /AuNPs), and the pre-adsorbed AuNPs served as nucleation sites for Au deposition.…”

Detection of Phenols from Industrial Effluents Using Streptomyces Mediated Gold Nanoparticles

“…Several basic and advanced physicochemical methods exist to monitor the presence of pesticides in polluted water samples [25]. Advanced techniques such as liquid and gas chromatography and mass photometry are highly sensitive, time consuming, and expensive and have greater limitations for the on-site or in-field analytical applications [26,27].…”