Abstract:

A novel colorimetric cross-responsive sensor array for protein identification was designed with prophyrin derivatves and dyes as chemical sensing elements. The 6×6 sensor array could react specifically with various proteins in 5 minutes, and it provided a color change profile before and after the reaction as a unique fingerprint for each specific protein. The image for each sample was then subjected to hierarchical cluster analysis(HCA), principal component analysis(PCA) and Euclidean distance calculation. Bovine serum albumin(BSA), Bovine hemoglobin(BHb) and Ovalbumin(Ova) as well as their mixtures, gave distinct patterns. In addition, native proteins and denatured ones could also be discriminated by the sensor array with high sensitivity, thus leading to their unambiguous identification. Furthermore, the sensor array showed a characteristic of temperature-dependence which visualized the whole heat-induced denaturation of protein. The results suggested that the unique pattern of colorimetric change may be due to the differences of protein conformation, local environmental pH and solubility. This is the essence of the protein discrimination. Therefore, the low cost and fast responsive colorimetric sensor array not only provide an excellent sensing platform for discrimination and quantitative analysis of protein samples, but also pave a new way for the mechanism study of heat-induced denaturation of protein and represent a potential application in real-time monitoring in the field of clinical medicine and food quality assurance.

Key words: Prophyrin, Colorimetric cross-responsive sensor array, Protein identification, Denatured protein