A novel continuous flow biosensor based on gold nanoparticles and poly(propylene-co-imidazole) was developed for the online determination of p-benzoquinone. The amperometric response was measured as a function of p-benzoquinone concentration at an applied potential of -50mV. The hydrogen peroxide concentration was optimized and fixed at 1mM in samples. The mass transfer resistance of the copolymer film was minimized, and the flow cell was regenerated quickly at 1mL/min. The resulting device provided good analytical performance based on a linear dynamic range from 5-100 mu M, a short response time of 3s, a detection limit of 3.3 mu M, excellent repeatability with a relative standard deviation of 0.82%, long-term stability of 95% after four weeks, and an accuracy of 105%. The gold nanoparticles enhanced the electron transfer rate on the electrode. The apparent Michaelis-Menten constant was 4mM, showing that the enzyme retained catalytic specificity and provided high activity for p-benzoquinone.