Portable Flow Injection Amperometric Sensor Consisting of Pd Nanochains, Graphene Nanoflakes, and WS₂ Nanosheets for Formaldehyde Detection

Abstract

Formaldehyde (FA) is a carcinogenic substance that can be found in various foods. A portable, highly sensitive, and rapid sensor comprising a flow injection amperometric analysis system and an enzyme-free electrode interface is proposed for the determination of FA sampled from foodstuffs. The electrode interface is based on a nanocatalyst of aggregated palladium nanochains anchored on a nanocomposite of graphene nanoflakes and tungsten disulfide nanosheets (PdNC−GNF/WS 2 ). The PdNC−GNF/ WS 2 electrode directly catalyzes the oxidation of FA at a low applied potential (−0.05 V vs Ag/AgCl) in an alkaline medium. The quantitative determination of FA was performed using a portable flow injection amperometric system connected wirelessly to a portable smart device. Under optimal conditions, the proposed sensor produced linear ranges from 0.010 to 10 mM and 10 to 100 mM with a sensitivity up to 220.6 μA mM −1 cm 2 . The limit of detection was 0.003 mM (0.10 mg L −1 ), and sample throughput was 60 samples h −1 . The antiinterference characteristics, repeatability, and reproducibility of the sensor toward FA determination were good. The proposed sensor successfully determined FA from food samples, achieving recoveries from 96 ± 4% to 103 ± 3% (n = 3). The obtained analytical performances and results support the potential of the proposed sensor in practical applications.

A Ternary Nanocomposite Based on Nano-Bimetallic Platinum/Nickel Decorated on Multi-Walled Carbon Nanotubes for Flow Injection Amperometric Detection of Promethazine

“…6B), perhaps due to reducing contact time between PMZ and the electrode interface, and reduced oxidation of PMZ. 35,36 Thus, the optimal carrier rate was 1.00 ml min −1 .…”

“…The slight drop and then the constant current response of PMZ detection by the nano-Pt/ Ni@MWCNT interface was due to saturation of the electrode sensing interface, signifying maximum reaction rate. 35,36 Therefore, the optimal sample volume was 250 μl.…”

Voltammetric Amitriptyline Determination Using a Metal-Free Electrode Based on Phosphorus-Doped Multi-Walled Carbon Nanotubes

“…The anti-interference performance of the P-MWCNTs/GCE towards each interfering species was assessed based on the tolerance limit ratio, which was defined as the highest concentration of an interfering substance that altered the current response of 5.0 μg ml −1 AMT with a relative error no greater than ± 5%. 57 The results are listed in Table S3. No significant influence was exerted on the detection of 5.0 μg ml −1 AMT by the presence of 50fold concentrations of glucose and ascorbic acid, 25-fold concentrations of uric acid and urea, 50-fold concentrations of sodium ion, potassium ion, calcium ion, magnesium ion, chloride ion, sulfate ion, and carbonate ion, and a 12.5-fold concentration of nitrate ion.…”

Highly Active Palladium-Decorated Reduced Graphene Oxides for Heterogeneous Catalysis and Electrocatalysis: Hydrogen Production from Formaldehyde and Electrochemical Formaldehyde Detection

“…However, the weak response behavior of FA at different concentration could be detected and the results were rather unsatisfactory. Moreover, although Pd NPs [ 45 ], Pd-Pt bimetallic NPs [ 46 ], and Pd nanochains/WS 2 nanosheets decorated graphene nanosheets [ 47 ] catalysts have shown preliminary advantages in FA detecting sensors, in the point view of practical application, they would still be hindered by high Pd loading, high overpotential, weak electrochemical response current, and a narrow electrochemical potential window of FA. Hence, there is incredible potential to develop versatile Pd based hybrids for FA detection, which possess excellent electrochemical response behaviors such as high sensitivity, a wide detection potential window, and lower overpotential by using lower Pd loading amount.…”