Absorption of sulfur dioxide gas in moistened porous material on a suspended gold leaf electrochemical sensor

• Published in: Sensors and actuators. B, Chemical Vol. 385; p. 133634
• Main Authors: Jantawong, Nanthatchaphon, Prasertying, Paithoon, Wongpakdee, Thinnapong, Khoonrueng, Nuttamon, Aroonchat, Purita, Fukana, Nutnaree, Wilairat, Prapin, Uraisin, Kanchana, Nacapricha, Duangjai
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2023
• Subjects: Electrochemical sensor; Gas medium; in-situ detection; Shrimp; Sulfite; Sulfur dioxide; Sulfite; in-situ detection; Electrochemical sensor; Gas medium; Sulfur dioxide; Shrimp
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2023.133634

This work describes an unconventional voltammetric detection in a gas medium using a suspended electrode unit. A paper moistened with the supporting electrolyte is used to absorb the gas. This concept was demonstrated for the in-situ detection of SO2 gas to quantify sulfite residue in samples of frozen shrimp. The gas is generated by the acidification of an aqueous suspension of shrimp tissues. The porosity of facial tissue paper is employed to provide a liquid layer of supporting electrolyte for the operation of the gold leaf electrochemical sensor. The absorbed gas is also dissolved in this liquid layer. The gold leaf sensor is reusable by replacing the tissue disc and rinsing the electrodes with water. The electrochemical sensor does not require refrigeration or pre-conditioning as with commercial biosensors and is thus suitable for point-of-need purposes. Production of the gold leaf sensor is only ca. 0.2 USD per unit and can be used regularly for up to 3 months. The linear calibration range of spiked negative control shrimp samples is from 3 to 240 mg kg−1 SO2 for a 30 mL solution of an extract of 5.0 g homogenized defrosted shrimp. The limit of detection (3 ×SDintercept/slope) for spiked samples is 2 mg kg−1 SO2. This is the first electrochemical sensor in a gas medium exploiting the entrapment of electrolyte solution inside a porous substrate. [Display omitted] •Concept of electrochemical detection in gas medium for zero-fouling of electrodes.•Moist facial tissue as disposable porous substrate for reusable gold leaf sensor.•A thin liquid layer as gas absorbent and background electrolyte.•Suitable for onsite analysis of sulfite residue in shrimp at regulatory levels.•Complete rapid point-of need unit without ex-situ extraction or centrifugation.