Preparation Of Cu-based Nanomaterials And Their Applications In Electrochemistry Sensing

Copper-containing nanomaterials have unique biological,physical and chemical properties.Due to their good electrical conductivity and optical properties,they have been regarded as become one of the most concerned transition metal nanomaterials gradually.They are widely applied in antibacterial,drug loading,photodynamic therapy,sensing,catalysis and many other fields.In addition to a comprehensive review of the classification,synthesis and application of copper-containing nanomaterials,this paper further explored the preparation of several copper-containing nanocomposites and their applications in electrochemical sensing.The specific work is as follows:1.A novel nanomaterial of two-dimensional holey CuCo₂O₄(2D HCCO)nanosheets was synthesized via a general template-directed method and employed for the first time to construct an effective electrochemical platform for H₂O₂sensing with the combination of cerium oxide(CeO₂).During the electrocatalytic reduction of H₂O₂,the synergetic catalysis of CeO₂/HCCO/MWCNTs/GCE owing to the naturally holey frameworks and the mediator of CeO₂results in the ultra-sensitive detection of H₂O₂.The current was greatly enhanced owing to the unique holey structure that can minimize the charge transfer distance and provide more active sites to boost the signals,and the dual oxidation state of Ce³⁺/Ce⁴⁺on the surface of 2D HCCO nanosheets can promote the in situ production of Cu²⁺/Cu⁺and Cu⁺/Cu and further amplify the detection signal.The CeO₂/HCCO/MWCNTs/GCE showed a wide linear range from 1?M to 7.31 m M using chronoamperometry at the potential of-0.25 V and a relatively low detection limit of 0.16?M in physiological environment,which was also utilized for tracking the trace H₂O₂released from Hela cells.This study shows great promise for the emerging application of holey HCCO-based biosensors in bioanalysis and early cancer diagnosis.2.Metastable cuprous oxide is one of the most attractive materials for constructing electrochemical sensing platforms among copper-containing nanomaterials.A novel coordination replication of Cu₂O redox-template strategy is reported to efficiently fabricate Au@Cu-MOF composite nanocapsules,with a Cu-MOF sandwich shell and an embedded Au nanoparticles layer.The porous metal organic framework(MOF)is grown in situ on Cu₂O,which provided Cu²⁺sources for the growth of Cu-MOF through reducing HAuCl₄into gold nanoparticles and transformed into Cu-MOF shell.The characterization results of the synthesized materials showed that Au@Cu-MOF composite nanocapsules were successfully synthesized.According to Cu/CuCl solid-state electrochemistry,it is a novel way to construct an electrochemical sensing platform signal amplification strategy.Inspired by the bimetallic synergy,porous structure of Au@Cu-MOF composite nanocapsules and Cu/CuCl solid-state electrochemistry,the feasibility of using Au@Cu-MOF composite nanocapsules in CuCl solid-state electrochemistry was explored.3.An ultrasensitive signal amplification strategy has been developed using Au@Cu-MOF nanocapsules as the electrochemical platform for the determination of glutathione(GSH)based on the signal output from the solid-state electrochemical of cuprous chloride(CuCl).The Au@Cu-MOF nanocapsule,with MOF sandwich shell encapsulated Au nanoparticle layer,was prepared via a coordinate replication of Cu₂O redox-template strategy.And the Au@Cu-MOF nanocapsules modified electrode achieved boosting signal output in the presence of chlorine ions(Cl^-)by solid-state electrochemistry of CuCl,which showed a pair of remarkable peaks.While in the presence of GSH,the phenomenon termed as“a crowding out effect”appeared,in which the specific Cu-GSH interaction triggered the competitive reaction with the conversion of CuCl into non-electroactive substance of Cu-GSH,leading to the sharp decrease in the peak current of CuCl.The Au@Cu-MOF nanocapsules modified electrode showed high sensitivity towards GSH owing to the specific electrochemical output at a relatively low potential,which can effectively shield the possible interferences in complex physiological surroundings.The“crowding out effect”can also improve the selectivity,particularly for complex analytical samples in terms of electrode fouling.The electrochemical sensor showed wide linear range of 0.01-40 n M and 40 nM-10?M,with the detection limit of 2.5 pM(S/N=3).The sensor can be utilized for the determination of GSH in various real vegetable and serum samples with satisfactory results.Besides,it can also be applied for probing GSH in the lysates of Romas cells with good sensitivity,which brings dawn for early diagnosis of cancer in clinic.Moreover,the ultrasensitive and selective solid-state CuCl electrochemistry promoted signal amplification strategy as well as the excellent stability and special nature of Au@Cu-MOF nanocapsules may promise their wide application in biological and food analysis fields.