Test stripes should deliver a rapid yes/no-answer or a semiquantitative result to the layman. We create such stripes by embedding suitable probes into polymer matrices that are coated onto a solid support. The picture below shows the response of test stripes to biogenic amines (BAs). Those are indicators of the freshness of protein-rich food because they are formed by enzymatic degradation upon ageing of food like fish, meat and cheese. Increasing concentrations of BAs are displayed by a red color. The stripes were designed to respond to BA-levels that are already toxic (and hence can induce food poisoning) but are below the odor threshold of the human nose.
Further analytes relevant for new test stripes are alcohols, aldehydes, ketones, pH and heavy metal ions. We employ microplate readers, spectrometers, digital cameras, mobile phones and digital pocket microscopes for the evaluation of stripes.
Selected publications:
- Yurova NS, Danchuk A, Mobarez SN, Wongkaew N, Rusanova TY, Baeumner AJ, Duerkop A, 2018, Functional Electrospun Nanofibers for Multimodal Sensitive Detection of Biogenic Amines in Food via a Simple Dipstick Assay, Anal Bioanal Chem, 410:1111-1121, DOI: 10.1007/s00216-017-0696-9.
- Bidmanova S, Steiner M-S, Stepan M, Vymazalova K, Gruber MA, Duerkop A, Damborsky J, Prokop Z, Wolfbeis OS, 2016, Enzyme based test stripes for the visual or reflectometric detection and quantitation of gaseous sulfur mustard, Anal Chem 88:6044-6049, DOI: 10.1021/acs.analchem.6b01272
- Steiner M-S, Meier, RJ, Duerkop A, Wolfbeis OS, 2010, Chromogenic Sensing of Biogenic Amines Using a Chameleon Probe and the Red Green Blue Readout of Digital Camera Images, Anal Chem, 82:8402-8405, doi: 10.1021/ac102029j