ABSTRACT
The excessive use of antibiotics in human and veterinary medicine causes the emergence of multidrug resistant bacteria. In this context, the surveillance of many different antibiotics provokes a worldwide challenge. Hence, fast and versatile multianalyte single-use biosensors are of increasing interest for many fields such as medical analysis or environmental and food control. Here we present a microfluidic platform enabling the electrochemical readout of up to eight enzyme-linked assays (ELAs), simultaneously. To demonstrate the applicability of this platform for the surveillance and monitoring of antibiotics, we used highly sensitive biomolecular sensor systems for the simultaneous detection of two commonly employed antibiotic classes tetracycline and streptogramin. Thus, microfluidic channel networks are designed, comprising distinct numbers of immobilization sections with a very low volume of 680 nL each. These passively metered sections can be actuated separately for an individual assay procedure. The limits of detection (LOD) are determined, with high precision, to 6.33 and 9.22 ng mL-1 for tetracycline and pristinamycin, respectively. The employed channel material, dry film photoresist (DFR), allows an easy storage of preimmobilized assays with a shelf life of at least 3 months. Multianalyte measurements in a complex medium are demonstrated by the simultaneous detection of both antibiotics in spiked human plasma within a sample-to-result time of less than 15 min.
