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RESEARCH HIGHLIGHT

DIFFERENTIAL-BASED BIOSENSOR

ARRAYS FOR DETECTING CARCINOGENS

IN HEAT-PROCESSED FOODS

Food contamination is a serious concern because a high Dr. Khor Sook Mei
level of chemicals in food causes severe health issues. Department of Chemistry
Safeguarding the public from the risk of adulterated foods
has become a challenging mission. Chloropropanols are Faculty of Science
Universiti Malaya
important to food safety and food security because they are naomikhor@um.edu.my
common chemical food contaminants and are believed to be
carcinogenic to humans.
In chemical sensing, chloropropanols are challenging analytes due to the lack of functional groups
and the difficulty in targeting the hydroxyl group in aqueous environments. Moreover, because of

their small molecular size, the compositions of chloropropanols remain challenging for achieving
chromatographic determination.
To simulate human smell and taste sensations, serum albumins, which are protein-based receptors,
were introduced as low-selective receptors for differential sensing. Utilizing serum albumins, a
fluorophore (PRODAN), and an additive (ascorbic acid), a differential-based optical biosensor array
was developed to detect and differentiate chloropropanols. By integrating the sensor array with linear
discriminant analysis (LDA), four chloropropanols were effectively differentiated based on their

isomerism properties and the number of the hydroxyl groups, even at an ultra-low concentration (5
nM). This concentration is far below the maximum tolerable level of 0.18 μM for chloropropanols. The
sensing array was then employed for chloropropanols differentiation and quantification in the complex
mixtures (e.g. synthetic soy and dark soy sauces). Leave-one-out cross-validation (LOOCV) analysis
demonstrated 100% accurate classification for all tests. These results signify our differential sensing

array as a practical and powerful tool to speedily identify, differentiate, and even quantify
chloropropanols in food matrices. The newly developed differential sensing array could be used by
industry, or any research laboratory for food safety control, monitoring, and the enforcement of food
safety regulations.

Figure 1: Schematic workflow

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