title: Probing chiral amino acids at sub-picomolar level based on bovine serum albumin enantioselective films coupled with silver-enhanced gold nanoparticles.
abstract: A novel electrochemical sensor with capability of probing chiral amino acids with gold nanoparticle (n-Au) labels using bovine serum albumin (BSA) as a chiral selector and subsequent signal amplification step by silver enhancement is introduced. The assay relies on the stereoselectivity of BSA embedded in ultrathin gamma-alumina sol-gel film coated on the surface of the glassy carbon electrode (GCE). The recognition to the n-Au-labeled L- or D-amino acids for BSA-GCE could be monitored by the differential pulse voltammetry (DPV), while the DPV signal was greatly amplified by the anchored silver atoms on the n-Au, leading to a new way of quantitatively analysis of chiral amino acids electrochemically at sub-picomolar level. With L-tryptophan as the probe solute, the linear concentration range was from 1.33 x 10(-12) to 1 x 10(-9)mol L(-1) and detection limit was 5 x 10(-13)mol L(-1). For tryptophan enantiomers, the enantioselectivity coefficient 2.3 was obtained.
authors.affiliation: Department of Chemistry, Fudan University, Shanghai, PR China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiuli
authors.initials: X
authors.lastname: Yin
authors.forename: Mianhong
authors.initials: M
authors.lastname: Shi
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Jilie
authors.initials: J
authors.lastname: Kong