Nanomaterials-modified electrochemical sensors for sensitive determination of alkaloids: Recent trends in the application to biological, pharmaceutical and agri-food samples

Alkaloids are a widespread group of secondary metabolites that occur naturally in a wide range of plant families. Many of them exhibit significant biological activity and therefore have numerous pharmacological applications. However, there is a great concern about the adverse effects (acute hepatotoxicity, genotoxicity and neurological damage) they may cause on consumers, as some of them are present in food. So, it is crucial to develop sensitive, selective and convenient sensors for alkaloids screening in different matrices. In this sense, the electrochemical detection platforms provide a promising analytical approach as it is economical, efficient, eco-friendly and easy to operate. Recently, some researchers have proposed electrochemical sensors based on nanomaterials as one of the powerful alternatives or complementary analytical tools to conventional time-consuming detection pro-cedures, as they have shown high performance in terms of sensitivity and selectivity. Nanomaterials are fundamental for developing electrochemical sensors in different applications, such as biomedical, pharmaceu-tical, environmental and food analysis. In this sense, this work presents a study on the applying different nanomaterials in detection platforms of alkaloids in agri-food, pharmaceutical and biological samples. Special attention has been paid to sensors developed with nanomaterials such as carbon-based materials, metal nano-particles, silica-based materials and imprinted molecular materials. Synthetical and technological aspects in developing sensors for alkaloids detection, current challenges and futures perspectives are included to provide an overview and suggestions for future research directions.