title: Surface Plasmon Resonance Imaging biosensor for cystatin determination based on the application of bromelain, ficin and chymopapain.
abstract: A Surface Plasmon Resonance Imaging (SPRI) sensor based on bromelain or chymopapain or ficin has been developed for specific cystatin determination. Cystatin was captured from a solution by immobilized bromelain or chymopapain or ficin due to the formation of an enzyme-inhibitor complex on the biosensor surface. The influence of bromelain, chymopapain or ficin concentration, as well as the pH of the interaction on the SPRI signal, was investigated and optimized. Sensor dynamic response range is between 0-0.6 μg/ml and the detection limit is equal to 0.1 μg/ml. In order to demonstrate the sensor potential, cystatin was determined in blood plasma, urine and saliva, showing good agreement with the data reported in the literature.
authors.affiliation: Department of Electrochemistry, Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443 Bialystok, Poland. ewka@uwb.edu.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Gorodkiewicz
authors.forename: Joanna
authors.initials: J
authors.lastname: Breczko
authors.forename: Anna
authors.initials: A
authors.lastname: Sankiewicz
mesh_terms: D015374:Biosensing Techniques; D001963:Bromelains / Q000737:chemistry / Q000378:metabolism*; D002917:Chymopapain / Q000737:chemistry / Q000378:metabolism*; D015891:Cystatins / Q000032:analysis* / Q000097:blood / Q000652:urine; D005361:Ficain / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D020349:Surface Plasmon Resonance
chemical_list: D015891:Cystatins; D055767:Immobilized Proteins; D001963:Bromelains; D005361:Ficain; D002917:Chymopapain