Kappa-casein based electrochemical and surface plasmon resonance biosensors for the assessment of the clotting activity of rennet
Φόρτωση...
Ημερομηνία
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Analytica Chimica Acta
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
We report for the first time the development of kappa-casein (kappa-CN)-based electrochemical and surface plasmon resonance (SPR) biosensors for the assessment of the clotting activity of rennet. Electrochemical biosensors were developed over gold electrodes modified with a self-assembled monolayer of dithiobis-N-succinimidyl propionate, while SPR measurements were performed on regenerated carboxymethylated dextran gold surfaces. In both types of biosensor, kappa-CN molecules were immobilized onto modified gold surfaces through covalent bonding. In electrochemical biosensors, interactions between the immobilized kappa-CN molecules and chymosin (the active component of rennet) were studied by performing cyclic voltammetry, differential pulsed voltammetry, and electrochemical impedance spectroscopy (EIS) measurements, using hexacyanoferrate(II)/(111) couple as a redox probe. kappa-CN is cleaved by rennet at the Phe105-Met106 bond, producing a soluble glycomacropeptide, which is released to the electrolyte, and the positively charged insoluble para-kappa-casein molecule, which remains attached to the surface of the electrode. This induced reduction of the net negative charge of the sensing surface, along with the partial degradation of the sensing layer, results in an increase of the flux of the redox probe, which exists in the solution, and consequently, to signal variations, which are associated with the increased electrocatalysis of the hexacyanoferrate(11)/(111) couple on the gold surface. SPR experiments were performed in the absence of the redox probe and the observed SPR angle alterations were solely attributed to the cleavage of the immobilized kappa-CN molecules. Various experimental variables were investigated and under the selected conditions the proposed biosensors were successfully tried to real samples. The ratios of the clotting power units in various commercial solid or liquid samples, as they are calculated by the EIS-based data, were almost identical to those obtained with a reference method. In addition, EIS measurements showed an excellent reproducibility, lower than 5%. (C) 2011 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
impedimetric biosensors, rennet, food analysis, kappa-casein, milk coagulation, surface plasmon resonance, milk, enzymes, micelle
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000300764700017
http://ac.els-cdn.com/S0003267011014875/1-s2.0-S0003267011014875-main.pdf?_tid=441a4c4327d198e2758fe160763b0a7e&acdnat=1333037232_d54414724ffcb072834b06df58533b1a
http://ac.els-cdn.com/S0003267011014875/1-s2.0-S0003267011014875-main.pdf?_tid=441a4c4327d198e2758fe160763b0a7e&acdnat=1333037232_d54414724ffcb072834b06df58533b1a
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας