Highly sensitive electrochemical sensor for rapid detection of Vibrio parahaemolyticus in Shrimp

A highly sensitive and selective electrochemical DNA sensor based on a carboxyl functionalized graphene oxide/single-stranded DNA/6-mercapto-1-hexanol/gold electrode (COOH/ssDNA/MCH/Au) was developed for the rapid detection of Vibrio parahaemolyticus in shrimp samples. The sensor exhibited excellent selectivity, with peak current ratios of 8.3 and 4.1 for complementary to non-complementary and one-base mismatched targets, respectively. It also demonstrated a wide linear range from 10 femtomolar to 10 nM, with a low detection limit of 3 femtomolar. The reproducibility of the sensor was good, with a relative standard deviation of 4.8% for five independently fabricated electrodes. When applied to the detection of V. parahaemolyticus in spiked shrimp samples, the sensor showed high accuracy, with recovery rates ranging from 92.5 to 108.3% and relative standard deviation values below 5%. The proposed sensor outperformed most previously reported electrochemical DNA sensors for V. parahaemolyticus detection in terms of sensitivity and linear range.