Point-of-care-testing of α-amylase activity in human blood serum.
Activity of α-amylase enzyme in human serum indicates the onset of pancreatitis, mumps, cancer, stress, and depression. Herein we design and develop a biosensor for the point-of-care-testing (POCT) of α-amylase concentration in serum. The biosensor is composed of a glass substrate coated with an electrically conducting poly-aniline-emeraldine-salt (PANI-ES) film covered with starch-coated gold nanoparticles (SAuNPs). Addition of different dosage of α-amylase on the biosensor selectively depletes starch stabilized on the SAuNPs, which changes the electrical resistance of the sensor. The change in electrical resistance show a nearly linear correlation with the concentration of α-amylase in buffer, which helps the detection of unknown α-amylase activity in the blood serum. The biosensor responds in a specific manner owing to the use of selective enzymatic chemical reaction between α-amylase and starch. The pathways to SAuNP formation on PANI-ES, time-dependent starch digestion with α-amylase, and the subsequent variation in electrical response was characterized to uncover the sensing mechanism. The chloride ions and the AuNPs present catalyse the starch-amylase reaction on the PANI surface to enable a sensitive detection of α-amylase in serum (25 - 100 U/l) at a quick response time of ~60 s. Integration of the biosensor with the built-in sourcemeter and a real time display help an immediate presentation of α-amylase level in the serum, comparable to the clinically approved methodologies.
['Mandal|Nilanjan|N|', 'Bhattacharjee|Mitradip|M|', 'Chattopadhyay|Arun|A|', 'Bandyopadhyay|Dipankar|D|']
D015374:Biosensing Techniques D006046:Gold D006801:Humans D053768:Metal Nanoparticles D019095:Point-of-Care Systems D013213:Starch D000516:alpha-Amylases
Point-of-care-testing α-amylase Biosensor Nanoparticles Starch Conducting polymer