Application Of Electrochemical Sensor Based On Nanoporous Gold In Detection Of Medical Fermention Product

Electrochemical sensor,as a chemical detection technology,was characteristized by its accuracy,high selectivity,fast response,and simple operation,which has been widely applicated in fermentation industry,food testing,drug testing,environmental protection,medical assays,and other fields in recent years.An electrochemical sensor is basically composed of a transducer and a recognition element,and the recognition element is the most important part.However,the existing recognition elements limited the application of electrochemical sensor in the fermentation products detection due to complex fermentational culture.Therefore,it is very necessary to develop new materials as the recognition element for electrochemical sensors construction.In this paper,nanoporous gold/glassy carbon electrode(NPG/GCE)is built,constructed using NPG as the recognition element.Due to its special structure and excellent physical and chemical properties,NPG has good catalytic performance for many substances,such as fermentation products.It is speculated that NPG may be an ideal recognition element of electrochemical sensor for the detection of fermentation products.Taking the fermentation products of ascorbic acid(AA)and dopamine(DA)as the research object,using NPG with its three-dimensional porous structure and unique physical and chemical properties as the recognition element,the NPG/GCE was constructed to implement the simultaneous detection of AA and DA(both are fermanted pharmaceutical substance)for its strong electric catalytic oxidation activity.The scanning electron microscopy(SEM)and three-dimensional structure model were used to characterize the continuous three-dimensional nanoporous meshy microstructures of NPG and nano-scale films with certain mechanical strength at the macro level.The electrochemical performance of NPG/GCE electrodes detecting AA and DA showed that the oxidation peaks of AA and DA were significantly separated and potential difference between two oxidation peaks was 150 mV.Meanwhile,the electrodes exhibited a good linear response to AA and DA with the least detection limits of 2.8 ?M and 0.17 ?M,and the sensitivity was up to 29.75 ?A mM-1 cm-2 and 1107.93 ?A mM-1 cm-2,respectively.In addition,NPG/GCE electrodes also showed excellent specificity,selectivity and anti-interference ability in the simultaneous detection of AA and DA.Based on the previous study,the detection of AA and DA with standard sample added in the actual fermentation medium was carried out to evaluate the detecting method.These excellent performances make the constructed NPG/GCE sensor an ideal choice for the detection of AA and DA in the fermentation process,which indicates a good application prospect in the future.Water-soluble vitamins,such as vitamin B2(VB2)and vitamin B6(VB6),are two common fermentation products.Therefore,the establishment of a simple,rapid and efficient method for the detection of VB2 and VB6 has significant meaning in controling parameter in the process of actual fermentation.The electrochemical behavior of VB2 and VB6 on NPG/GCE electrode surface characterized by CV method is a progress of diffusion control.And the detection principle of NPG/GCE electrode for VB2 and VB6 was also discussed.On this basis,the independence,selectivity and simultaneous detection of VB2 and VB6 was implemented by the constructed NPG/GCE electrochemical sensor.The linear range of NPG/GCE electrode for simultaneous detection of VB2 and VB6 was 20?250 and 40?800 ?M,respectively.The sensitivity of NPG/GCE electrode was 143.9 ?A mM-1 cm-2 and 32.57 ?A mM-1 cm-2 with the least detection limits of 0.2 ?M and 0.3 ?M,respectively.Futhermore,the results of anti-interference experiment show that the electrode has strong anti-interference ability to the common anions,cations and possible carbon sources in the fermentation medium,with satisfying stability and repeatability.In addition,the electrode was used to detect VB2 and VB6 with standard sample added in the fermentation medium,which verified the reliability of NPG/GCE in the sample detection.These excellent sensing properties indicated that the constructed NPG/GCE electrodes have the satisfying application potential in independent,selective and simultaneous detection of VB2 and VB6.Based on the previous work,NPG is found to have a strong catalytic activity toward tetracycline antibiotic chlortetracycline(CTC).Therefore,based on its high catalytic activity and good conductivity,an NPG/GCE electrochemical sensor was constructed to detect CTC.DPV method and Ampertromitric i-t curve(i-t curve)method were used to optimize the most appropriate pH and detection potential,and eventually the optimum condition is determined to be pH 8.0 and detection potential of 0.16 V.Under the optimum condition,CTC was detected by i-t curve method.The results of electrochemical detection showed that there is a well linear relation between the concentration and the peak current density within the concentration range of 1?M-2 mM,and the minimum detection limit was 42 nM and the sensitivity was 6.27?A mM-1 cm-2.The anti-interference ability of electrodes showed that the interference of 10 times substrate concentration on the detection of CTC was less than 3.18%,investigated by using common anions,cations and carbon sources in fermentation medium.Thus,the excellent anti-interference performance made the NPG/GCE electrode a good choice for the detection of CTC in fermentation products.In addition,the electrode was used to detect CTC from the fermentation medium with standard sample added,and the results of detection were stable and reliable.Hence the constructed NPG/GCE electrode was expected to realize on-line,rapid,efficient,and sensitive detection of CTC in the fermentation process.It would become an effective technique with broad application prospects in the field of oxytetracycline detection.This study focused on the application of nanoporous gold-based sensor for rapid and efficient detection of pharmaceutical fermentation products.NPG with unique physical and chemical properties and high efficiency electrocatalytic oxidation characteristics was selected as the recognition element of the electrochemical sensor.And NPG/GCE electrode was constructed to detect the pharmaceutical fermentation products.The constructed sensor showed high catalytic activity,good selectivity and strong anti-interference in the detection of fermentation products.It also has the advantages of good sensor stability,simple preparation,good repeatability,long service life and low cost.Besides,the electrochemical sensor,based on nanomaterials,overcome the disadvantages of biosensor which is complexly prepared and greatly affected by the environment,is expected to realize on-line,rapid,efficient and sensitive detection of pharmaceutical fermentation products.