Voltammetric determination of leucovorin in pharmaceutical preparations using a boron-doped diamond electrode

Towards voltammetric point of care detection of leucovorin

Current healthcare trends have seen an increased emphasis on the move towards personalised precision medicine to tailor treatments to the individual and their response to diseases and disease therapies. This highlighting a transition from traditional "one size fits all" to a more nuanced approach. Despite advancements in fundamental knowledge to facilitate personalised prevision approaches, lack of resources to implement such plans remains one of the largest hurdles to overcome. Monitoring of drug therapies is one key aspect that could aid in the evolution of precision medicine alongside the development of drugs and targeted treatment systems. This contribution illustrates the potential of square wave voltammetry (SWV) as a proof-of-concept for monitoring of circulating blood concentrations of treatment therapies within artificial urine, using leucovorin calcium (LV) as a model cancer therapy drug. A low cost, easy-to-use and portable sensor has been developed and successfully employed for the detection of LV over the linear range 0.5-30 μM which represents the therapeutically relevant concentrations for LV within artificial urine without any prior sample preparation required with a limit of detection of 2.63 μM and initial investigations into saliva and serum as biological matrices. The developed sensor describe herein exhibits a proof-of-concept for the engagement of such electrochemical sensors as point-of-care devices, where the sensors ease of use and removal of time-consuming and complex sample preparation methods will ultimately increase its usability by physicians, widening the avenues where electrochemical sensors could be employed.

Boron-Doped Diamond Electrodes: Recent Developments and Advances in View of Electrochemical Drug Sensors

Conductive boron-doped diamond (BDD), in addition to its superior material properties, offers many important advantages that make it an interesting material for electroanalytical studies. It has been considered as an excellent electrode material for electrooxidation of drug active compounds in their dosage forms or in biological materials due to its good physical and chemical properties. It contains not only the largest solvent working potential window compared to other electrode materials, but also it has low background and capacitive currents; lower problems with passivation and it has the ability to withstand extreme potentials, corrosive, and high temperature/pressure environments. The aim of this review is not only to provide a state-of-the-art of diamond electrochemistry but also to serve as a reference point for any researcher wishing to commence work with diamond electrodes and understand electrochemical data. Therefore, it is focused on the carbon-based materials, electrochemical properties of the BDD film electrode, its fundamental research, and its electrochemical pretreatment process are discussed in detail. In this case, there are important studies to show the effective BDD drug sensors for the detection and determination of drugs and the present review critically summarizes the available data in this field between 2015 and 2020.