Enzyme-based Nanoparticle Biosensors for Rapid Detection of Heavy Metals in Food Samples

Heavy metal contamination of food and water samples is a serious environmental and health problem that requires rapid and sensitive detection methods. In this study, we developed an enzyme-based nano biosensor for detecting heavy metals using sol-gel synthesis of selenium oxide nanoparticles and crude protease enzyme extract from chicken intestine. The biosensor works by measuring the change in temperature after dipping the biosensor in a sample, which reflects the interaction between the heavy metals and the enzyme. We tested our biosensor on five common heavy metal salts (chromic chloride, copper (II) sulfate, mercuric chloride, cadmium carbonate, and arsenic chloride) and observed different responses in terms of temperature change and color change. Our biosensor showed high efficiency and accuracy for detecting heavy metal contamination at 1% concentration, but it also had some limitations such as low selectivity and sensitivity. We suggested some potential improvements and applications of our biosensor, such as coupling it with electronic devicessuch as thermometer or modifying it with different enzymes or nanoparticles. Our biosensor has a wide range of applications for various industrial sectors, such as pharmaceutical, cosmetic, waste water treatment, battery, paper, textile, coal, oil, leather, steel, thermal power, and dye intermediaries.