High throughput LSPR and SERS analysis of aminoglycoside antibiotics

Aminoglycoside antibiotics are used in the treatment of infections caused by Gram-negative bacteria, and are often dispensed only in severe cases due to their adverse side effects. Patients undergoing treatment with these antibiotics are therefore commonly subjected to therapeutic drug monitoring (TDM) to ensure a safe and effective personalised dosage. The ability to detect these antibiotics in a rapid and sensitive manner in human fluids is therefore of the utmost importance in order to provide effective monitoring of these drugs, which could potentially allow for a more widespread use of this class of antibiotics. Herein, we report on the detection of various aminoglycosides, by exploiting their ability to aggregate gold nanoparticles. The number and position of the amino groups of aminoglycoside antibiotics controlled the aggregation process. We investigated the complementary techniques of surface enhanced Raman spectroscopy (SERS) and localized surface plasmon resonance (LSPR) for dual detection of these aminoglycoside antibiotics and performed an in-depth study of the feasibility of carrying out TDM of tobramycin using a platform amenable to high throughput analysis. Herein, we also demonstrate dual detection of tobramycin using both LSPR and SERS in a single platform and within the clinically relevant concentration range needed for TDM of this particular aminoglycoside. Additionally we provide evidence that tobramycin can be detected in spiked human serum using only functionalised nanoparticles and SERS analysis.