Synthesis And Nonenzymatic Glucose Sensing Performance Of Copper-Based Nanomaterials

Recently, more and more people suffer from diabetes mellitus, so it is important to establish a rapid, accurate and reliable method to detect and analyze the blood glucose in the clinical and practical application. The majority of commercially available glucose sensor is enzyme glucose sensor, however, these sensors are limited due to their poor stability and reproducibility. The enzymeless glucose sensors exhibit excellent catalytic activity toward glucose oxidation on the electrode direct ly, not only can avoid the drawbacks of the enzyme, but also provide a new way for detection the blood glucose concentration rapidly. Among the variety of nonenzymatic glucose sensor electrode materials, people pay more attention to the copper(Cu) and copper oxide(C uO) because of their excellent conductivity, low-cost and excellent electrocatalytic activity toward the direct oxidation of glucose.This paper focuses on design and synthesis of Poly(p-phenylenediamine)/Copper(PpPD/C u) composites and different morphology of CuO. Nonenzymatic glucose sensor were fabricated by these nanomaterials, as-prepared sensors showed excellent electrocatalytic activity, good reproducibility, stability and selectivity toward the direct oxidation of glucose. The main contents of this paper are summarized as follows:(1) Poly(p-phenylenediamine) nanosheets were first synthesized through oxidative polymerization of p-phenylenediamine and were then used as the substrate for anchoring copper microspheres via a facile solvothermal route. The resultant Poly(p-phenylenediamine)/Copper(PpPD/C u) composites possess good electrical conductivity, big specific surface area, large pore size and pore volume. The as-prepared PpPD/Cu showed excellent electrocatalytic activity toward the direct oxidation of glucose in the absence of any enzymes. Under the optimal conditions, the PpPD/Cu-based enzymeless glucose sensor showed short response time(i.e., the current achieved 95% of the steady state value within 3s), wide linear range(0.003-6.44 mM), high sensitivity(929 μA·mM-1·cm-2), low detection limit(4.48×10-7 mol·L-1), good reproducibility and selectivity. In addition, the as-prepared PpPD/C u-based enzymeless glucose sensor was successfully applied for quantitative determination of glucose in real serum samples with recoveries ranging from 99.5 % to 101.1 %, showing great promise for clinical application.(2) Carnation- like CuO hierarchical nanostructures assembled by ultrathin porous nanosheets were successfully fabricated via a facile solvothermal ro ute with Cu(AC)2, ethylene glycol(EG), and urea, followed with heat treatment. As-prepared C uO nanostructures exhibited excellent catalytic activity toward glucose oxidation in the absence of any enzymes. Under the optimized conditions, the C uO-based enzymeless glucose sensor showed high sensitivity of 3.15 mA·mM-1·cm-2, low limit of detection(98 nM, S/N=3), good reproducibility, excellent selectivity and long-time stability. Moreover, the CuO-based enzymeless glucose sensor showed high accuracy and reliability in comparison with clinical glucometer for quantitative determination of glucose in human blood serum samples.(3) CuO nanoribbon were prepared b y a simple synthesis method with C u(AC)2, potassium, and isopropanol(IPA), followed with heat treatment. Modified electrode(CuO/GCE) were prepared using C uO as modifier.The experimental results showed that as-prepared CuO nanoribbon exhibited excellent catalytic activity toward glucose oxidation directly in the alkaline conditions. Under the optimized conditions, the CuO-based enzymeless glucose sensor showed a wide linear range of 0.002-6.15 mM, high sensitivity of 1522.3 μ A·mM-1·cm-2, low limit of detection of 2.8×10-7 mol/L(S/N=3), good reproducibility and long-time stability, excellent selectivity, can resistance to uric acid, dopamine and the common carbohydrates and some inorganic salts interferents.(4) A facile one-step hydrothermal route and heat treatment were developed to synthesize C uO nanomaterial were prepared by copper acetate and sodium hydroxide as raw materials, with the help of dispersant sodium dodecyl benzene sulfonate(SDBS). The electrochemical behavior of glucose on the CuO/GCE was studied by cyclic voltammetry and chronoamperometry. The results indicated that the as-prepared CuO/GC E showed high electrocatalytic activity toward the direct oxidation of glucose in 0.15 M NaOH. Under the optimized conditions, the prepared CuO enzymeless glucose sensor showed a wide linear response in the range from 3.5 μM ~ 4.2 mM, high sensitivity of 987.3 μA·mM-1·cm-2, and low detection limit down to 2.8×10-7 mol/L(S/N=3). This biosensor showed favorable stability and reproducibility, can resistance to dopamine, uric acid, ascorbic acid and immune to the poisoning of chloride ion.