Green chemistry approach to formaldehyde detection using fish albumin-modified gold electrodes

BACKGROUND AND OBJECTIVES: Formaldehyde in food or the environment poses significant health risks, as it is a known carcinogen that can cause respiratory issues skin irritation, and long-term exposure can lead to serious diseases such as cancer. It can be found around us, such as in food and water. A novel gold electrode modified with fish albumin has been developed for the detection of formaldehyde, aligning with green chemistry principles. Fish albumin, which contains amino acids such as glycine, lysine, and histidine, can react with formaldehyde. This reactivity suggests that fish albumin is a viable and environmentally friendly material for use in formaldehyde sensors. The objectives of this study were to make albumin-modified electrodes used for formaldehyde detection applied for the fish in case fishermen generally use formaldehyde to preserve the fish they bring ashore. This formaldehyde helps maintain the freshness of the fish during the handling and transportation process.METHODS: The fish albumin was used from the self-extraction of snakehead fish (Channa striata) using water as a solvent. Fish albumin was mixed with paraffin in a definite ratio, then heated on the hot plate and stirred until homogenized. The liquid was poured into a small glass tube, with one of the ends connected to gold. The electrode was ready to be used after the liquid became solid. All performances for formaldehyde detection used the cyclic voltammetry technique. The potential measurement was between 0 volt and +1.8 volt with a 100 millivolt per second scan rate.FINDINGS: The electrode works well in acidic conditions by showing a significant formaldehyde signal compared to alkaline and neutral conditions. The linear analysis range was 0.1 ~ 3 millimolars with a detection limit of 4.07 micromolars, and the sensitivity was 20.365 microampere millimolars per square millimeter. This electrode was used to determine the formaldehyde concentration in the interference of methanol, ethanol, glycerol, and glucose. This method was also applied to the real samples and simultaneously compared to the standard method (Nash method) for formaldehyde detection.CONCLUSION: The electrode exhibits excellent performance with high sensitivity and selectivity for formaldehyde detection under acidic conditions. The electrode also features a low detection limit, allowing for precise formaldehyde measurement. Methanol, ethanol, glucose, and glycerol do not interfere with detection. Additionally, the electrode demonstrates good repeatability and delivers accuracy comparable to the standard Nash method, making it a promising alternative for formaldehyde detection. The benefit of the proposed method is that no reagent is added to samples.