| Rutin,also named vitamin P,is considered as an active therapeutic medicine that can be used for the prevention and treatment of hypertensive cerebral hemorrhage.In addition,rutin has functions of anti-inflammatory,anti-tumor,and anti-oxidant,which shows certain reactive oxygen intermediate scavenging activities,such as hydroxyl radical,superoxide radical and peroxy radical.Tannic acid(TA)is widely applied in both research and industry filed,such as its application for an addictive in medical products for treating diarrhea and burns,clarifying agent and flavoring agent in food industry,as well as its great importance for re-tanning in combination with Cr(III)salt to prevent leather putrefaction.Moreover,as an organic chemical agent,TA is considered as a pollutant that may contaminate the aquatic ecosystem.In view of their widespread uses,effective and fast detection methods for rutin and TA are urgently sought.Recently,owing to the good properties such as convenience,fast response,low detection limits and good stability,electrochemical methods have attracted much attention,especially for the electrode material,which plays an important role in electrochemical analysis.Noble metallic nanoparticles like Pt and Au nanoparticles have been widely used for electrochemical determination on account of their unique advantages of enhanced mass transport,size controlled electrical,chemical and optical properties.Besides,semiconductor materials also attract considerable attention in electrochemical applications due to their unique optical,electrical properties and other properties such as low cost,nontoxic and nature abundance.However,in order to cut down the cost,novel metal nanoparticles modified on metal oxides is considered to be an effective strategy to decrease the usage of novel metals.Based on the optical properties of metal oxide semiconductor,photo-electrochemical approach for the determination of small molecules has been also studied.In our work,electrochemical methods and photo-electrochemical methods are used for the analysis of rutin and TA,separately.The main contents are as follows:(1)A nonenzymatic electrochemical sensor based on chemically reduced graphene oxide(RGO)and Pt nanoparticles(Pt NPs)modified glassy carbon electrode has been fabricated and used to determine rutin.The nanocomposites of Pt NPs/RGO were characterized by transmission electron microscopy and X-ray diffraction,and the electrochemical behaviors of Pt NPs/RGO were demonstrated by cyclic voltammetry(CV)and different pulse voltammetry(DPV).The as-fabricated electrochemical sensor for rutin exhibited a wide linear range from 0.057 to 102.59 ?M with a detection limit of 0.02 ?M(S/N = 3).Additionally,the as-prepared electrode displayed a good reproducibility,stability and anti-interference ability for the detection of rutin.Finally,the electrode was successfully applied for the determination of rutin in pharmaceutical tablets.(2)The nanocomposites,consisting of Cu2 O,Au nanoparticles and nitrogen-doped graphene(denoted as Cu2O-Au/NG)were successfully fabricated by a facile and green method and used for highly sensitive detection of rutin.The electrochemical methods,such as CV and DPV have been used to investigate the electrochemical properties of the fabricated sensors for rutin detection.The results showed that the Cu2O-Au/NG/GCE under optimal conditions could exhibited the highest sensitivity of 114.94 ?A.m M-1 compared with other modified electrodes,and a low detection limit of 30 n M(S/N = 3)which could be achieved with a linear concentration response range from 0.06 to 512.90 ?M.The enhanced electrochemical performances could be attributed to the synergistic effect between Cu2O-Au and NG as well as the outstanding catalytic effect of the Cu2O-Au nanoparticles.Finally,the sensor was successfully used to analyze rutin tablets,showing high potential for practical applications.(3)Flower-like ZnO-Pt materials with three-dimensional architectures were synthesized by one-pot method,and a novel TA analytical method based on flower-like Zn O-Pt modified glassy carbon electrode(Zn O-Pt/GCE)was also developed.Due to the introduction of metal Pt on Zn O,the as-prepared electrode exhibited good conductivity and gave rise to a significant increase in the photocurrent density under UV light illumination,confirming an enhanced charge transfer speed and a well combination between exited electron-hole pairs of Zn O.For the analysis of TA,DPV was applied to evaluate the photoelectrochemical performance on Zn O-Pt/GCE,and a wide linear range of 0.04-72.34 ?M with a low detection limit of 0.02 ?M(at S/N = 3)was obtained ultimately.The oxidation mechanism of tannic acid in different routes was also proposed and discussed.Moreover,the prepared electrode displayed high stability and selectivity toward the determination of tannic acid. |
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