An innovative biosensor utilizing aptamer-gated mesoporous silica nanoparticles for determination of aminoglycoside antibiotics through indirect-lateral flow.

Background: Aminoglycoside antibiotics (AGs) are commonly utilized in both human and veterinary medicine to treat and manage a range of infections. These antibiotics are recognized for their narrow therapeutic window, with an overdose potentially resulting in severe side effects like kidney and ear damage. Hence, the implementation of a quick, precise, and on-the-spot testing method is crucial in clinical settings. In the present investigation, we designed an innovative indirect lateral flow assay (LFA) utilizing aptamers to detect kanamycin, a type of aminoglycoside antibiotics. We prepared mesoporous silica nanoparticles (MSNs) functionalized with amino groups, loaded them with morphine (MOP), and then sealed them with aminoglycoside aptamers (Apt). The complex of gated-MSNs@Apt was tested using the MOP LFA in the presence or absence of kanamycin antibiotics.

Results: The indirect LFA system displayed a single colored line in the test line for positive samples, whereas it exhibited double colored lines in both the control line and test line for negative samples. Our custom-designed LFA biosensors demonstrated two linear ranges, from 10 nM to 350 nM and 500 nM-1500 nM, with a limit of detection (LOD) of 5 nM in serum media under optimized conditions. The introduced indirect LFA biosensor was effectively utilized to detect kanamycin, achieving a satisfactory recovery rate of 92.9-109.9 % with RSD of 1.68-7.73 % in serum samples.

Significance: In general, the created LFA system offers a portable, straightforward, and affordable approach for point-of-care (POC) identification of kanamycin and other AGs.