Electrosynthesized poly(1,6-hexanedithiol) as a new immobilization matrix for Au-nanoparticles-enhanced piezoelectric immunosensing

Chemical/Biochemical Preparation of New Polymeric Bionanocomposites with Enzyme Labels Immobilized at High Load and Activity for High-Performance Electrochemical Immunoassay

“…As is well known, AuNPs with strong adsorbility and biocompatibility have been widely used as immobilization substrates of biomolecules. , Here, we further introduced AuNPs to the PDA−PtNPs−GOx bionanocomposites by using a biochemical-synthesis protocol. In brief, HAuCl 4 and glucose were added to a suspension of the PDA−PtNPs−GOx bionanocomposites in sequence; then, the enzymatic reaction generated H 2 O 2 to reduce HAuCl 4 to AuNPs, as shown in Scheme (path I).…”

“…For comparison with the proposed protocol of the biochemical synthesis of AuNPs, we also adopted two commonly used protocols to introduce AuNPs to the PDA−PtNPs−GOx bionanocomposites, that is, the direct adsorption of preformed AuNPs , and the chemical synthesis of AuNPs. , For the direct-adsorption protocol, we prepared AuNPs of ca. 20 nm diameter with trisodium citrate as the reductant and stabilizer according to the well-established procedures, ,, then mixed these AuNPs (see sample 1 in Figure ) with the PDA−PtNPs−GOx bionanocomposites that had been rinsed with water at least five times for saturated adsorption. For the chemical-synthesis protocol, the procedures are similar to those for the biochemical-synthesis protocol, except that 0.20 mM HAuCl 4 and 4.0 mM H 2 O 2 (instead of glucose) were added into the PDA−PtNPs−GOx suspension in sequence.…”

“…40,41 For the direct-adsorption protocol, we prepared AuNPs of ca. 20 nm diameter with trisodium citrate as the reductant and stabilizer according to the well-established procedures, 11,22,24 then mixed these AuNPs (see sample 1 in Figure 2) with the PDA-PtNPs-GOx bionanocomposites that had been rinsed with water at least five times for saturated adsorption. For the chemical-synthesis protocol, the procedures are similar to those for the biochemicalsynthesis protocol, except that 0.20 mM HAuCl 4 and 4.0 mM H 2 O 2 (instead of glucose) were added into the PDA-PtNPs-GOx suspension in sequence.…”

“…The polymeric nanocomposites (PNCs) of polymer, nanoparticles, and more components have attracted much attention for their obvious scientific and technical interests in various fields, including biosensing . The main merits of the PNCs as biomaterials are as follows: (1) the polymer matrix with high processability and functionality can efficiently entrap and adsorb the species of interest, such as biomolecules − and nanoparticles; , (2) nanoparticles with significant adsorbability and biocompatibility both in and on the PNCs can provide the PNCs with abundant sites to bind biomolecules and retain the bioactivity; ,, (3) the incorporation of plenty of nanoparticles can endow the PNCs with diversified functions for developing biodevices, involving catalysis, ,, electronics, optics, and magnetics; and (4) the PNCs is cost-effective, stable, and convenient in preparation. Virtually, our recent work has demonstrated that the polydopamine (PDA)−glucose oxidase (GOx)−Pt nanoparticles (PtNPs) PNCs can readily entrap the enzyme at high load/activity for highly sensitive glucose biosensing; therein, the load and activity of GOx entrapped in a film of this PNCs are 2.2- and 4.2-folds of those in a PDA film electrosynthesized in the presence of GOx, respectively, yielding a detection sensitivity as high as 129 μA cm −2 mM −1 for glucose biosensing, which is among the best sensitivities of various reported GOx electrodes .…”

“…h i b i t e d .substrates of biomolecules 11,22. Here, we further introduced AuNPs to the PDA-PtNPs-GOx bionanocomposites by using a biochemical-synthesis protocol.…”