Investigation of Ruthenium–based pyridine substituted 1,2,4–Triazole–5– ylidenes complexes as molecular electrocatalysts in the effective detection of date rape drugs

Numerous new psychoactive substances have been introduced into the drug market over the past decade mainly with an intention to implement their use for clinical purposes. However, the necessity of updated screening approaches for their quantification within the clinically required concentrations is crucial to avoid drug abusive incidents. Present work describes a study on the application of suitably designed N–heterocyclic carbene (NHC) coordinated ruthenium(II) p–cymene complexes for the detection of date rape drugs (DRDs) such as ketamine and scopolamine. The study highlights the synthesis of two structurally–tuned ruthenium(II) NHC complexes bearing pyridine and benzyl/benzonitrile substituted 1,2,4–triazol–5–ylidene ligand and their spectral and analytical characterization. Further, the preparation of the working electrodes using ruthenium(II) NHC complexes for electrochemical measurements evidenced the ultra–trace level detection of predatory drugs like ketamine and scopolamine, with limit of detection as low as 0.275 and 4.379 nM, respectively. Developed ruthenium NHC complexes are cost–effective, easy–to–use and successfully employed for the detection of DRDs at pertinent concentrations using an aqueous electrolyte. Furthermore, the title ruthenium derivatives are stable, hence upon real time analyses, could be employed in the assembly of point–of–care devices. Alongside, these electrochemical sensors can potentially simplify the conventional protocols that are time–consuming and demand tedious sample preparation methods; therefore, the usage of these organometallics by forensic scientists in the investigation of drug abuse cases opens up new avenues.