title: Self-tuning interfacial architecture for Estradiol detection by surface plasmon resonance biosensor.
abstract: This study reports the operation principles for reusable SPR biosensors utilizing nanoscale-specific electrostatic levitation phenomena in their sensitive layer design. Functional macromolecular building blocks localized near the "charged" surface by a variety of weak electrostatic interactions create a flexible and structurally variable architecture. A proof-of-concept is demonstrated by an immunospecific detection of 17β-Estradiol (E2) following the competitive inhibition format. The sensing interfacial architecture is based on the BSA-E2 conjugate within the BSA matrix immobilized on the "charged" (as a result of guanidine thiocyanate treatment) gold surface at pH 5.0. Kinetic analysis for different E2 concentrations shows that using parameter β of the stretched exponential function ~(1-exp(-(t/τ)β) as an analyte-specific response measure allows one to substantially decrease the low detection limit (down to 10-3ng/ml) and increase the dynamic range (10-3-103ng/ml) of the SPR biosensor. Finally, it's concluded that the created interfacial architecture is a typical complex system, where SPR response is formed by the stochastic interactions within the whole variety of processes in the system. The E2 addition destroys the uniformity of the reaction space (where an interaction of the antibody (Ab) and the analog of E2 in the self-tuneable matrix takes place) by the redistribution of the immunospecific complexes Ab(E2)x(x=0, 1, 2) dependent on E2 concentration. Binding dynamics changes are reflected in the values of β which summarize in compact form all "hidden" information specific for the evolving distributed interfacial system.
authors.affiliation: V. Lashkaryov Institute of Semiconductor Physics, NAS Ukraine, 41 Prospect Nauki, Kyiv 03028, Ukraine.
authors.forename: Praskoviya
authors.initials: P
authors.lastname: Boltovets
authors.affiliation: University Bordeaux, UMR 5255, ISM, F-33000 Bordeaux, France; INSERM, U862, Neurocentre Magendie, F-33000 Bordeaux, France.
authors.forename: Svitlana
authors.initials: S
authors.lastname: Shinkaruk
authors.affiliation: University Bordeaux, UMR 5255, ISM, F-33000 Bordeaux, France; CNRS, UMR 5255, ISM, F-33405 Talence, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Vellutini
authors.affiliation: V. Lashkaryov Institute of Semiconductor Physics, NAS Ukraine, 41 Prospect Nauki, Kyiv 03028, Ukraine. Electronic address: snopok@isp.kiev.ua.
authors.forename: Borys
authors.initials: B
authors.lastname: Snopok
mesh_terms: D015374:Biosensing Techniques; D004958:Estradiol / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000276:immunology; D020349:Surface Plasmon Resonance
chemical_list: C043090:estradiol-bovine serum albumin; D012710:Serum Albumin, Bovine; D004958:Estradiol; D006046:Gold
keywords: Biosensor; Complex systems; Electrostatic levitation; Estradiol; Stretched exponential function; Surface plasmon resonance