Probing trace Pb(2+) using electrodeposited N,N'-(o-phenylene)-bis-benzenesulfonamide polymer as a novel selective ion capturing film.

A novel film modified electrode for the determination of trace lead was developed in this work. The modified electrode was prepared by the electropolymerization of N,N'-(o-phenylene)-bis-benzenesulfonamide (PBSA) as the ion capturing reagent to create the functional film. The modified electrode shows a high selectivity towards Pb(2+) over interfering cations, e.

Probing chiral amino acids at sub-picomolar level based on bovine serum albumin enantioselective films coupled with silver-enhanced gold nanoparticles.

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.

A mediator-free screen-printed amperometric biosensor for screening of organophosphorus pesticides with flow-injection analysis (FIA) system.

A mediator-free amperometric biosensor for screening organophosphorus pesticides (OPs) in flow-injection analysis (FIA) system based on anticholinesterase activity of OPs to immobilized acetylcholinesterase enzyme (AChE) has been developed. The enzyme biosensor is prepared by entrapping AChE in Al(2)O(3) sol-gel matrix screen-printed on an integrated 3-electrode plastic chip. This strategy is found not only increase the stability of the embedded AChE, but also effectively catalyze the oxidative reaction of thiocholine, making the Al(2)O(3)-AChE biosensor detects the substrate at 0.

Site-specific protein immobilization in a microfluidic chip channel via an IEF-gelation process.

A novel strategy for site-specific protein immobilization via combining chip IEF with low-temperature sol-gel technology, called IEF-GEL here, in the channel of a modified poly(methyl methacrylate) (PMMA) microfluidic chip is proposed in this work. The IEF-GEL process involves firstly IEF for homogeneously dissolved protein in PBS containing alumina sol and carrier ampholyte with prearranged pH gradient, and then gelation locally for protein encapsulation. The process and feasibility of proposed IEF-GEL were investigated by EOF measurements, fluorescence microscopic photography, Raman spectrum and further demonstrated by glucose oxidase (GOx) reactors integrated with end-column electrochemical detection.

Multianalyte immunoassay based on insulating-controllable PoPD film at arrayed electrodes integrated on a silicon chip.

A novel, simple and label-free multianalyte immunoassay system is presented here by integrating arrayed electrodes on a silicon chip via MEMS. The chip is consisted of six Au disk electrodes, an Au counter electrode and an Ag/AgCl reference electrode. Semi-insulating poly(o-phenylenediamine) (PoPD) was utilized to co-polymerize and immobilize antibodies at the arrayed Au electrodes, and wider linear detection range was obtained than those prepared with completely insulating PoPD.

Immunoassays based on microelectrodes arrayed on a silicon chip for high throughput screening of liver fibrosis markers in human serum.

A novel immunoassays for screening of disease markers in human serum are presented by miniaturizing interdigitated array (IDA) of microelectrodes via micro electro-mechanical system (MEMS) on a silicon chip for multi-channel electrochemical measurement. Different selected antibodies (Abs) are incorporated site-specifically into the electrochemically deposited polypyrrole (PPy) formed on the IDA of the silicon chip, which was characterized by fluorescence microscope photo and the electrochemical quartz crystal microbalance (EQCM) measurements. The selective recognition of Ab to the corresponding antigen (Ag) is monitored through the measurable conductivity change, which is directly visualized by cyclic voltammograms (CVs) in presence of the redox probe, Fe (CN)6(3-/4-).