Gold Nanoparticles for Advanced Chemosensing Applications

Chemosensors

Chemosensors transduce chemical stimuli into measurable electrical signals. They are pivotal in biology, medical diagnostics, and environmental monitoring, enabling rapid, selective detection of analytes.

Gold Nanoparticles (AuNPs)

AuNPs are prized for their high surface‑to‑volume ratio and surface‑dominated chemistry, which confer superior catalytic activity compared to bulk gold. These properties have been leveraged in electro‑catalysis, where AuNPs serve as nanoelectrodes that enhance electron transfer rates.

Electrochemical Sensor Design

Common anchoring strategies—electrostatic adsorption, covalent coupling, and electrochemical deposition—create robust AuNP–electrode interfaces. Such nanoengineered surfaces exhibit a markedly higher faradaic to capacitive current ratio, lowering analytical detection limits.

Advances in Nanoelectrode Ensembles

Researchers have engineered 2‑D and 3‑D AuNP‑modified electrode arrays that deliver superior electrochemical responses. For example, AuNPs self‑assembled on a sol‑gel 3D silicate matrix can detect neurotransmitters like norepinephrine, dopamine, catechol, epinephrine, and ascorbic acid with enhanced sensitivity.

Non‑Enzymatic Glucose Sensor

By functionalizing a thiol‑terminated silicate network with AuNPs and treating it with hydroxylamine, glucose oxidation can be catalyzed at lower potentials without enzymes or redox mediators. This configuration achieves a detection limit of 50 nM in phosphate buffer, outperforming many conventional sensors (Lee et al., 2022).

Toxic Metal and Gas Detection

AuNP‑modified carbon screen‑printed, glassy carbon, and pyrolytic graphite electrodes enable sensitive detection of Sb(III) and As(III). Moreover, AuNPs on a sol‑gel 3D network or via seed‑mediated growth provide exceptional catalytic activity for nitric oxide and hydrazine oxidation, yielding ultra‑low detection thresholds (Kim & Park, 2021).

These advances underscore the pivotal role of gold nanoparticles in next‑generation chemosensors, combining high sensitivity with operational simplicity.