The quality and quantity analysis of hazardous toxicants may be an important issue and is an interesting area for researches. Investigation of chemical and microbial analysis is the purpose of this work. The rapid detection of pathogens, microbial toxins and other hazardous environment toxicants is critical for ensuring human health and safety, especially for products (food) with short shelf lives. Chemical contaminants may occur from various sources. They typically pose a health concern, resulting in strict regulations of their levels by national governments and internationally by the Codex Alimentarius Commission. Therefore, analysis of relevant chemical contaminants is an essential part of safety testing program to ensure consumer safety and compliance with regulatory and tolerance limits.<br/>Modern analytical techniques can determine known chemical contaminants in complex at very low concentration levels. Recently, innovative approaches with material science engineers are developing with better collaborations of biological engineers for discovering novel materials to insure Biosafety levels. We here demonstrated a non-labeled portable plasmonic biosensor for selective detection of Salmonella typhimurium melamine in food samples. Briefly, a plasmonic sensor applying the self-assembly of the gold nanoparticles of 20nm, was used to conduct high-density deposition on a transparent substrate in order to achieve a regulated diameter of Au NP monolayer, which produced longitudinal wavelength extinction shifts through the localized surface plasmon resonance (LSPR) signal. The developed aptamers conjugated the LSPR sensing chips revealed an ultra-sensitive limit of detection (LOD) for S. typhimurium as ~104 cfu/mL in pure culture under the optimal assay conditions with a total analysis time of 30~35 min. As an another application, the rapid lateral flow immunoassay (LFIA) was suggested for on-site detection of melamine in milk products. Melamine is an organic compound, often used with formaldehyde to produce melamine resins due to its high nitrogen levels. Also, melamine forms insoluble melamine cyanurate crystals in the kidneys. In this study, LFIA is not only rapid detection of melamine, but also can be melamine detection in infant formula. These findings confirm that the developed Au NPs-aptamer-based LSPR sensing chip am have practical applications for the sensitive detection of melamine in food samples.

Development of portable sensor chip for toxic chemicals and microbial toxins in food and environment

2019 Spring National Meeting

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