Molecularly Imprinted QCM Sensor Based on Hollow ZIF-67@PDA for Sparfloxacin Detection

In this study, we present the design of a molecularly imprinted polymer (MIP) for the detection of the antibiotic sparfloxacin (SPFK), combined with a high-precision quartz crystal microbalance (QCM) sensor. Green-synthesized ZIF-67@PDA-MIP was directly immobilized on the gold electrode surface of the QCM. This configuration takes advantage of the selective recognition capabilities of the MIP and the high-sensitivity response characteristics of the QCM sensor. It overcomes the limitations of traditional SPFK detection methods, offering both accurate detection and rapid responses for practical applications. The MIP-QCM sensor demonstrated enhanced sensitivity and affinity, achieving a detection limit as low as 10.3 ng/mL. Additionally, the selectivity of the sensor for SPFK was superior to that of other non-template molecules. It effectively detected SPFK residues in milk with acceptable accuracy, as indicated by recoveries ranging from 96.16% to 104.64% and a relative standard deviation (RSD) of less than 4.64%. These results suggest that the proposed MIP-QCM sensor provides an accurate, sensitive, rapid, and cost-effective method for detecting SPFK residues in animal products, and this advancement is expected to promote the widespread adoption of high-precision sensors in food safety testing.