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Abstract. A quantitative rapid analysis method for ofloxacin detection in raw milk using molecule-specific recognition and an electrochemical impedance spectrum (EIS) technique was investigated in this study. An association complex (AC) formed by a combination of ofloxacin and sodium tetraphenylboron (ST) was used as the active material for electrochemical analysis. A carbon screen-printed electrode (CSE) was modified with the AC to form an electrochemical active membrane for ofloxacin detection. EIS data of pretreated raw milk samples were measured and analyzed with a non-linear bistable stochastic resonance (SR) model. Trace ofloxacin concentrations were characterized by SR output signal-to-noise ratio (SNR) eigen values. An ofloxacin quantitative analysis model was built based on SNR eigen values. Experimental results demonstrated that the proposed method presented good accuracy, repeatability, and recovery. It is a promising way for ofloxacin detection in raw milk. Keywords: Association complex, Electrochemical impedance spectrum, Ofloxacin, Quantitative analysis, Sodium tetraphenylboron.

Sugar is one of the important content within food. The classic sugar determination method is precise but needs fuzzy operation, which indicating the high cost. With the rapid development of functional materials in the past decades, a glucose sensor with small size is supposed utilizing the popular nano-sized materials. In this paper, glucose quantitative detecting system was proposed using graphene oxide (GO) modified foam nickel electrode, Pt electrode, and Ag/AgCl electrode. Na 2 CO 3 , NaOH, and NH 3 in different concentrations were utilized to explore the optimized basic solution. Cyclic voltammetry (CV) and current-time (i-t) scanning were accepted to study the linear relationship between glucose concentration and current density. Results demonstrated that the optimized basic solution content was an equal volume of Na 2 CO 3 and NaOH according to sensor's sensitivity and responding current density. However, the responding sensitivity of optimized basic solution became weaker than pure NaOH basic solution. In order to increase chemical sensitivity of the electrode, GO was used to modify foam nickel electrode. Results indicated that the responding current was effectively increased. The responses presented good linear relationship with glucose concentration (I = 0.226 c + 0.8289, R 2 = 0.9998). The detecting limit was 13.3 μmol/L. The presence of GO in foam nickel structure tremendously increased the detecting sensitivity. The decrease of NaOH volume in basic solution proposed a green way for this technique in sugar rapid analysis, glucose analysis in blood.