title: Chiral recognition of mandelic acid on quartz crystal microbalance by vapor diffused molecular assembly method.
abstract: This study presents a new approach for the highly selective recognition of chiral L/D-mandelic acid (MA) using a quartz crystal microbalance (QCM) with L-phenylalanine (L-Phe) as the selector. The immobilization of L-Phe on the gold surface of the QCM sensor was performed using a four steps layer-by-layer assembling procedure. The modification of the gold surface of the QCM sensor after each modification step was verified by the cyclic voltammetry, contact angle, FTIR, and QCM detection. The chiral recognition ability of L- and D-MA on the chiral surface was checked by sensing using the vapor diffused molecular assembly (VDMA) method with the QCM. The chiral discrimination factor between L- and D-MA, aplha(L-MA/D-MA), was found to be about 9. The L-Phe-modified QCM gold sensor also showed good stability and reusability. The high chiral discrimination ability of the modified surface might be the result of the different hydrogen bonding force between L- or D-MA and L-Phe.
authors.affiliation: Department of Chemistry, Shaoguan University, Shaoguan 512005, China.
authors.forename: Hui-Shi
authors.initials: HS
authors.lastname: Guo
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Sang-Mok
authors.initials: SM
authors.lastname: Chang
authors.forename: Woo-Sik
authors.initials: WS
authors.lastname: Kim
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D007536:Isomerism; D008333:Mandelic Acids / Q000032:analysis* / Q000737:chemistry; D010649:Phenylalanine / Q000138:chemical synthesis / Q000737:chemistry*; D011791:Quartz / Q000737:chemistry; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D008333:Mandelic Acids; D011791:Quartz; D010649:Phenylalanine; D006046:Gold; C037938:mandelic acid