title: Aptamer-MIP hybrid receptor for highly sensitive electrochemical detection of prostate specific antigen.
abstract: This study reports the design and evaluation of a new synthetic receptor sensor based on the amalgamation of biomolecular recognition elements and molecular imprinting to overcome some of the challenges faced by conventional protein imprinting. A thiolated DNA aptamer with established affinity for prostate specific antigen (PSA) was complexed with PSA prior to being immobilised on the surface of a gold electrode. Controlled electropolymerisation of dopamine around the complex served to both entrap the complex, holding the aptamer in, or near to, it's binding conformation, and to localise the PSA binding sites at the sensor surface. Following removal of PSA, it was proposed that the molecularly imprinted polymer (MIP) cavity would act synergistically with the embedded aptamer to form a hybrid receptor (apta-MIP), displaying recognition properties superior to that of aptamer alone. Electrochemical impedance spectroscopy (EIS) was used to evaluate subsequent rebinding of PSA to the apta-MIP surface. The apta-MIP sensor showed high sensitivity with a linear response from 100pg/ml to 100ng/ml of PSA and a limit of detection of 1pg/ml, which was three-fold higher than aptamer alone sensor for PSA. Furthermore, the sensor demonstrated low cross-reactivity with a homologous protein (human Kallikrein 2) and low response to human serum albumin (HSA), suggesting possible resilience to the non-specific binding of serum proteins.
authors: Department of Electronic & Electrical Engineering, University of Bath, Bath BA2 7AY, United Kingdom. Electronic address: P.Jolly@bath.ac.uk.
authors: Pawan
authors: P
authors: Jolly
authors: School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, United Kingdom. Electronic address: Tamboliv@cardiff.ac.uk.
authors: Vibha
authors: V
authors: Tamboli
authors: School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom. Electronic address: rob.harniman@bristol.ac.uk.
authors: Robert L
authors: RL
authors: Harniman
authors: Department of Electronic & Electrical Engineering, University of Bath, Bath BA2 7AY, United Kingdom. Electronic address: P.Estrela@bath.ac.uk.
authors: Pedro
authors: P
authors: Estrela
authors: School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, United Kingdom. Electronic address: Allendercj@cardiff.ac.uk.
authors: Chris J
authors: CJ
authors: Allender
authors: School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, United Kingdom. Electronic address: Bowenjl2@cardiff.ac.uk.
authors: Jenna L
authors: JL
authors: Bowen
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques; D058266:Dielectric Spectroscopy; D006046:Gold / Q000737:chemistry; D006801:Humans; D007610:Kallikreins / Q000097:blood*; D008297:Male; D054802:Molecular Imprinting; D011108:Polymers / Q000737:chemistry; D017430:Prostate-Specific Antigen / Q000097:blood*; D012709:Serum Albumin / Q000302:isolation & purification; D020840:Tissue Kallikreins / Q000302:isolation & purification
chemical_list: D052157:Aptamers, Nucleotide; D011108:Polymers; D012709:Serum Albumin; D006046:Gold; C549870:KLK3 protein, human; D007610:Kallikreins; D020840:Tissue Kallikreins; D017430:Prostate-Specific Antigen
keywords: Aptamer; Electrochemical impedance spectroscopy; Molecular imprinting; Prostate cancer; Prostate specific antigen