“Naked” gold nanoparticles as colorimetric reporters for biogenic amine detection

Detection of Sub-Nanomolar Concentration of Trypsin by Thickness-Shear Mode Acoustic Biosensor and Spectrophotometry

“…In colorimetric sensor applications, AuNPs are most widely used due to their high stability, facile synthesis, excellent biocompatibility, and strong surface plasmon resonance effect. This effect can be utilized to produce visual color changes in a process termed the colorimetric method [ 53 , 54 ]. Here, we report the results of a simple colorimetric assay based on the optical properties of functionalized AuNPs ( Figure 2 ).…”

Food Quality Monitoring Based on Hydrolysis‐Induced Au‐Catalyzed Heck Cross‐Coupling by Ag Metallization

“…The foodborne illness caused by pathogens, toxins, and other contaminants is a serious risk to human health. Conventional methods for detecting pathogenic bacteria and toxins are time consuming and relatively difficult, requiring special laboratory equipment and experienced operator [1][2][3]. Nanomaterials, including metal oxides as well as metal nanoparticles, carbon nanotubes, and quantum dots, play an important role in the design of sensors and biosensors for food analysis [4].…”

“…In recent years, much research has been done on the design of nanoscale materials to identify pathogenic bacteria [2,4]. Gold nanoparticles have been widely used for various sensors due to their unique properties [1,10]. Chemicals on the nanoparticle surface can be controlled by organic bond-forming agents such as thiol molecules or thiol-containing polymers, resulting in a high particle affinity for bonding with sulfhydryl groups (which form relatively strong covalent bonds) [1,11].…”

“…Gold nanoparticles have been widely used for various sensors due to their unique properties [1,10]. Chemicals on the nanoparticle surface can be controlled by organic bond-forming agents such as thiol molecules or thiol-containing polymers, resulting in a high particle affinity for bonding with sulfhydryl groups (which form relatively strong covalent bonds) [1,11]. Further modification of the surface of gold nanoparticles can be performed by molecules with thiolated functional groups, binding to various probes including antibodies and nucleic acids [4].…”

“…The surface plasmon group results from the accumulation of electrons attached to the conductive group due to the small particle size. The change in the surface plasmon group depends on the particle size, the surrounding chemicals, the particle surface adsorption capacity, and their dielectric constant [1,10]. Local changes in the dielectric current of nanoparticles, by adsorption of biomolecules or induction of biomarkers of nanoparticles, cause changes in localized surface plasmon resonance (LSPR) [13].…”