Molecular Differentiation of Cathepsins B and D, and of p53 Protein, and their Quantitative Assay in Biological Samples

Abstract

Cathepsins B, D and protein p53 are three of the biomarkers with a large spectrum of implications in the field of physiopathology as many diseases proved to be associated with their variation in concentration. Therefore, there is a need for reliable tools able to perform molecular recognition/differentiation, and also reliable quantification of cathepsins B, cathepsin D, and protein p53. Two stochastic microsensors based on diamond/graphene nanopowders modified with 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine manganese (III) chloride were proposed for the simultaneous differentiation and quantification of cathepsins B, D and protein p53 in whole blood, urine, saliva, and tumoral tissues. The lowest limits of determination and the highest sensitivities were recorded when the stochastic microsensor based on nanopowder of graphene was used. Wide linear concentration ranges were recorded for both microsensors. The recovery values obtained for the microsensors, were higher than 97.00%, and the relative standard deviations values were lower than 1.00%, when used for screening of whole blood, urine, saliva, and tumoral tissues.