Preparation Of Gold Nanoparticle Composites And Their Application In Meat Detection

Meat is the necessity for people daily life. With the development of living standard, meat quality has received the widespread attention. Four main aspects of meat quality detection are edible quality, processing quality, nutritional value and safety health quality, respectively. Among this, the meat edible quality, mainly including meat color, tenderness, juiciness and flavor, has a larger impact on the consumer demands. The traditional detection method of meat quality is mostly complicated, time-consuming and low sensitivity, which cannot satisfy the demands of modern meat industry. Therefore, it is significant to find a convenient, fast and highly sensitive method of meat quality detection. Biosensor is a kind of technology which combines biological and electrical analysis. It has received wide attentions, due to its specificity,high speed,high efficiency and accuracy. In this paper,some commom substances related to meat color and tenderness (myoglobin, hemoglobin and heat shock protein) are selected as the research object. Biosensors are constructed for meat quality qu,antitative detection. The concrete research content is as follows:(1) A label-free electrochemical aptasensor based on RGD-Au NPs for myoglobin detectionA label-free electrochemical aptasensor (MBA/RGD-Au/APTES/GCE) using linear arginine-glycine-aspartate (RGD) conjugated gold nanoparticles (RGD-Au NPs)as conductive material and myoglobin-binding-aptamer (MBA) as receptor was reported to determine myoglobin (Mb). The performance of the electrochemical aptasensor was measured by cyclic voltammetry (CV) and electrochemical impedance spectra (EIS). Under the optimized conditions, such as the temperature, incubation time and pH value of buffer solution, the anodic peak currents were proportional to the concentration of Mb from 0.0002 to 0.2 mg/mL. The linear regression equation was I (?A) = 168.18 - 336.00 c (mg/mL) (R2=0.9948) with the detection limit of 50.13 ng/mL. The aptasensor had a good anti-interference property towards glucose oxidase (GOx), cytochrome C (Cy.C) and hemoglobin (Hb). Moreover, the method is expected to be applicable to the evaluation of meat freshness and quality.(2) A non-enzymatic biosensor based on SiO2-Au NPs for hemoglobin detectionA simple non-enzymatic hemoglobin (Hb) biosensor with the help of SiO2-Au nanoparticles (SiO2-Au NPs) was prepared and investigated. The structure and morphology of SiO2-Au NPs were characterized by transmission electron microscope(TEM) and UV-vis. Fourier transform infrared spectra (FTIR) and circular dichroism(CD) spectra were used to testify the biocompatibility of SiO2-Au NPs. The electrochemical properties were measured by cyclic voltammetry (CV),electrochemical impedance spectra (EIS) and differential pulse voltammetry (DPV).Under the optimized conditions, the linear regression equation between the peak currents and the concentration of Hb was i (?A) = -51.57269 + 83.14106 c (mg/mL)(R2=0.9979) with the detection limit of 204.46 ng/mL. In addition, the electrochemical biosensor possessed good anti-interference performance. Due to superior performance of SiO2-Au NPs, it shows great potential in applications for direct sensing of Hb for evaluating the meat quality.(3) A immunosensor based on g-C3N4-F127-Au NPs for heat shock protein 90 detectionA novel method was established to fabricate a highly sensitive immunosensor for quantitative detection of heat shock protein 90 (HSP90). The novel immunosensor was built based on g-C3N4-F127-Au NPs modified electrode. The transmission electron microscope (TEM) was measured to the structure and morphology of g-C3N4-F127-Au NPs. The successful preparation of g-C3N4-F127-Au NPs was characterized by UV-vis spectra, fourier transform infrared spectra (FTIR) and Raman spectra. Circular dichroism (CD) spectroscopy was performed to test the secondary structure of HSP90 and estimate the biocompatibility of g-C3N4-F127-Au NPs.Meanwhile, the electrochemical properties were measured by linear sweep voltammetric (LSV) and differential pulse voltammetry (DPV). Under the optimized conditions, the peak currents were linear with the concentration of HSP90 in the range of 0.049 to 2.43 mg/mL. The linear regression equation was I (?A) = -18.2960 +3.4498 c (mg/mL) (R2=0.9945) with the detection limit of 27.01 ng/mL. Finally, the immunosensor exhibited good anti-interference performance and provided a new approach for meat quality evaluation.