Controllable Growth And Non-enzymatic Sensing Properties Of Cu-based Nanomaterials

Cu-based nanomaterials have been applied in sensing fields due to their high richness,low cost,and unique chemical properties.However,most of the non-enzymatic electrochemical sensors,with low detection range and high cost,need to be improved in sensitivity and selectivity.It is an effective method to improve the sensing properties of Cu-based nanomaterials by changing the morphology and forming heterostructures.First,this paper provides a preparation method of hexagonal Cu NSs with high purity,the two-dimensional structure of Cu NSs is regulated by controlling the ripening time of Cu seeds and the reduction rate of copper citrate.Due to the unique anisotropy and“Clean Surface”of two-dimensional Cu nanomaterials,they exhibit excellent sensitivity and a wide detection range in non-enzymatic electrochemical sensing.The glucose detection range is 0?36.0 m M,and the sensitivity is 560.9?A·m M^-1·cm^-2,which is higher than that of the Cu NSs-R synthesized by surface assisted method,and the enhanced factor up to 2.11.The detection range of nitrite and H₂O₂is up to 0?5.0 and 0?10.0 m M.In addition,the obtained Cu NSs also showed good catalytic performance in the reduction of 4-nitrophenol.Second,this paper also provides a preparation method of high-purity Cu nanowires(Cu NWs),the obtained Cu NWs is uniform in size,and the Cu NWs diameter can be regulated from 40?300 nm.The results show that the introduction of HCl solution not only reduces the nucleation,but also etches small nanoparticles and improves the purity of Cu NWs.The one-dimensional Cu NWs showed excellent performance in the application of constructing enzyme-free glucose sensing.The sensitivity to glucose was up to 1001.8?A·m M^-1·cm^-2,which was better than Cu NWs-300(338.3?A·m M^-1·cm^-2)containing particles,the enhanced factor up to 2.96and detection range was up to 0?25.0 m M.It has better anti-interference properties and is more suitable for the detection of glucose in human serum.Then,this paper also uses the sacrificial template method to synthesize Cu NWs composite Pd heterostructure(Cu NWs@Pd),and its diameter can be controlled in the range of 40?180 nm.It is shown that the synergistic effect of bimetal can not only improves the sensitivity of the constructed sensors,but also realize the detection of low potential.Compared with pure Cu NWs,Cu NWs@Pd showed a higher sensitivity(1363.7?A·m M^-1·cm^-2)with a detection limit of 3.07?M at a high potential of 0.8 V(vs Ag/Ag Cl).Meanwhile,Cu NWs@Pd can detect high concentrations of glucose at a low potential of 0.2 V(vs.Ag/Ag Cl)with a detection range of 0?26.0 m M.At the same time,Cu NWs@Pd also has excellent sensing properties for H₂O₂detection,with a sensitivity of 88.1?A·m M^-1·cm^-2at room temperature and the detection range from 0.5 to 4.0 m M.Finally,a further study of the sensing properties of semiconductor Cu-based nanomaterials,provides a synthesis method of Cu Br@Pt nanoparticles(Cu Br@Pt NPs).The diameter of the Cu Br@Pt NPs was regulated by changes in the synthetic temperature.In the formation of Cu Br@Pt NPs,the introduction of H₂Pt Cl₆played a dual role:the formation of elemental Pt particles on the surface of Cu Br improves the performance of the sensor;the other is to inhibit Cu Br NPs ripening and improve the dispersion and uniformity of particles.The obtained Cu Br@Pt NPs is used to construct a non-enzymatic glucose sensor.Compared with pure Cu Br NPs,the Cu Br@Pt NPs(674.1?A·m M^-1·cm^-2)sensor showed good sensitivity with enhanced factor is up to 5.5.The enhanced sensitivity attributed to the synergy effect of surface elemental Pt nanoparticles on glucose-catalyzed oxidation,which enhanced the response current density,and the presence of Pt nanoparticles enhanced the surface charge transport characteristics.The smaller size favored more active sites and enhanced the toxicity resistance of Cu Br@Pt NPs,when the size of Cu Br@Pt NPs was reduced to 70?80 nm,the constructed enzyme-free sensor showed excellent glucose detection performance with a detection range of 0?70.0 m M.In this paper,four Cu-based nanomaterials were prepared by liquid phase method,with simple,low cost and green synthesis process.Compared to precious metals materials,Cu-based nanomaterials have the characteristics of wide detection range and high sensitivity in the building of enzyme-free sensing process.Given the low cost of metal Cu and the high sensing properties,this work presents new ideas for the new enzyme-free electrochemical sensor design.