Molecularly imprinted poly[bis(2,2'-bithienyl)methane] film with built-in molecular recognition sites for a piezoelectric microgravimetry chemosensor for selective determination of dopamine.
A piezoelectric microgravimetry (PM) chemosensor, featuring a film of molecularly imprinted polymer (MIP) of poly[bis(2,2'-bithienyl)methane] bearing either a 3,4-dihydroxyphenyl or benzo-18-crown-6 substituent, for selective determination of dopamine was devised and tested. A Pt/quartz resonator and a dopamine-templated MIP film, deposited by electropolymerization onto an underlayer of poly(bithiophene), served as the transducer and recognition element of the chemosensor, respectively. The UV-vis spectroscopic and XPS as well as electrochemical measurements verified completeness of the dopamine template extraction with a strong base solution. The extraction-generated molecular cavities featured recognition sites that served selective dopamine analyte binding. The SECM imaging substantiated the permeability characteristics of the template-free MIP film. The dopamine analyte was determined under FIA conditions with the PM detection. The lower limit of detection was 10nM dopamine at favorable conditions involving the 35 μL/min carrier solution flow rate and the injected sample volume of 1 mL. The sensitivity of the chemosensor increased almost fivefold when the poly(bithiophene) film coated Pt/quartz electrode was used instead of the bare Pt/quartz electrode as the substrate for deposition of the MIP film. The chemosensor successfully discriminated dopamine from structural and functional analogues, such as 2-phenylethylamine, histamine, and ascorbic acid. The optimum mean thickness of the MIP film was ∼220 nm.
Pietrzyk
Agnieszka
A
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
Suriyanarayanan
Subramanian
S
Kutner
Wlodzimierz
W
Maligaspe
Eranda
E
Zandler
Melvin E
ME
D'Souza
Francis
F
D001205:Ascorbic Acid / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D043844:Crown Ethers / Q000737:chemistry; D004298:Dopamine / Q000032:analysis* / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D006632:Histamine / Q000032:analysis; D008697:Methane / Q000737:chemistry*; D054802:Molecular Imprinting / Q000295:instrumentation / Q000379:methods*; D010627:Phenethylamines / Q000032:analysis; D056951:Photoelectron Spectroscopy; D010984:Platinum / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011791:Quartz / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013876:Thiophenes / Q000737:chemistry*; D014159:Transducers
D043844:Crown Ethers; D010627:Phenethylamines; D011108:Polymers; D013876:Thiophenes; D011791:Quartz; C029261:phenethylamine; D010984:Platinum; C015762:18-crown-6; D006632:Histamine; D008697:Methane; D001205:Ascorbic Acid; D004298:Dopamine