Smart chemometrics-assisted electrochemical biosensor for alkaline phosphatase detection

A novel electrochemical biosensor was developed for selective and sensitive determination of alkaline phosphatase (ALP) based on its reaction with para -Nitrophenylphosphate (pNPP) as an enzyme-substrate reaction. Abnormal ALP levels are associated with many diseases, including breast cancer, bone tumor, thyroid disease and liver disease. A rotating glassy carbon electrode (GCE) was modified with multiwalled carbon nanotubes-ionic liquid (MWCNTs-IL) and pNNP (pNNP-MWCNTs-IL/GCE). The ALP was able to catalyze the hydrolysis of pNPP liberating inorganic phosphate and the conjugate base of para-nitrophenol to generate negative charges at the biosensor surface which attracted [Ru(NH 3 ) 5 Cl] 2 + molecules carrying positive charges to the surface of the biosensor and caused the biosensor response changed. Effects of experimental parameters on response of the biosensor were optimized by a central composite design (CCD) as an advanced chemometric approach. Under optimized conditions, first-order advantage was exploited from first-order amperometric data as an efficient and advanced chemometric approach by modeling them with PLS-1, rPLS, LS-SVM, PCR, CPR, RCR, BP-ANN, WT-ANN, PRM, DWT-ANN, RBF-ANN, and RBF-PLS to select the best algorithm to assist the biosensor for determination of ALP in blood samples having complex matrices. Our results confirmed LS-SVM showed the best performance to assist the biosensor for selective and sensitive determination of ALP whose results were comparable with ELISA kit. The biosensor assisted by LS-SVM was long-term stable, repeatable, reproducible, sensitive, and selective which could be suggested as a reliable method for determination of ALP in blood samples.