Gold Nanoparticle-Modified Tungsten Oxide Flakes as Nitric Oxide Sensor Electrodes for Fruit Quality Monitoring

Abstract

Development of low-cost, handheld nitric oxide (NO) sensors is very much important due to its major role in environmental pollution, biomedical research, and food safety applications. In this study, an electrochemical NO sensor has been fabricated using gold nanoparticle (Au NP)-modified tungsten oxide (WO 3 ) nanoflakes. WO 3 nanoflakes were grown hydrothermally on fluorine doped tin oxide (FTO) substrates, and Au NPs were attached by a photoreduction method. The sensing characteristics of pristine WO 3 and Au NP-coated WO 3 electrodes have been studied by amperometric techniques. The sensor performance has been optimized at various Au NP loadings. The optimized sensor demonstrated a high sensitivity (∼39.37 μA cm −2 mM −1 ) over a wide linear range (∼10 μM to 5.78 mM) with a low detection limit (∼0.12 μM). The Au NP-coated WO 3 sensing electrode demonstrated high stability. The sensor current only decreases 7.54% after 31 days of continuous measurements. The sensor also showed fast response (1.7 s) and high selectivity toward NO detection. NO detection in fruit samples (apple and orange) has been studied with the Au NP-modified WO 3 electrode for fruit quality monitoring application.

Combining nitric oxide and calcium sensing for the detection of endothelial dysfunction

“…The nanoprobe also showed high selectivity in the presence of other ROS and RNS like H 2 O 2 , ClO − , ONOO − , NO 2 − and NO 3 − . Other nanoparticle-based systems for NO sensing developed recently include probes based on Ce-based metal−organic framework 135 , aminoguanidine hydrochloride and citric acid-based carbon-dots 136 , 4-(((3-aminonaphthalen-2-yl)amino)methyl)benzoic acid functionalized CdTe/CdS/ZnS quantum dots 137 , electrochemically active gold nanoparticle-modified tungsten oxide (WO 3 ) nanoflakes 138 , or Au nanoparticles that undergo azide–alkyne click chemistry-mediated aggregation-based NO sensor 139 .…”

A novel electrochemical biosensor based on WO3@AuNPs and HBP@BIBB macromolecule-triggered ATRP for DR1 detection

“…12 It has been demonstrated that ultrathin WO 3 nanosheets can endow WO 3 with high conductivity and further improve the sensitivity of the sensor relative to bulk WO 3 . 13 Similarly, gold nanoparticles (AuNPs), as a common functional nanomaterial, have been widely used in the field of sensing attributed to their unique physicochemical properties, such as good chemical stability, high surface area, and fast electron transfer properties. [14][15][16] For example, Jin et al electrodeposited AuNPs onto a modified glassy carbon electrode surface and constructed a novel, sensitive and label-free aptasensor for ratiometric electrochemical sensing of dopamine.…”

Fruit Freshness Monitoring Employing Chemiresistive Volatile Organic Compound Sensor and Machine Learning

“…Technologies for detecting and monitoring fruit volatiles include gas chromatography–mass spectroscopy (GC-MS), , electrochemical, colorimetric, e-nose, surface-enhanced Raman spectroscopy, optical, piezoelectric sensor, and organic field effect transistors . Standard GC-MS equipment and laser-based optical sensors, however, are often very expensive and are not appropriate for portable applications or on-site monitoring analyses.…”