Recent developments of bioanalytical methods in determination of neurotransmitters in vivo

Neurotransmitters (NTs) constitute an important group of messenger molecules and their imbalance lead to various neurological disorders, making their analytical determination of great importance in both laboratory and clinical practice. Here we review the most recent progress in sample pretreatment and in vivo analysis for various NTs and metabolites focusing on two approaches: biosensors and SPME, which require small amounts of biological samples and have wide application. Biosensors, as integrated analytical tools, provide the chance for direct monitoring of NTs and their dynamics directly in a tissue. In turn, non-exhaustive SPME method enables a high-throughput and effective extraction of endogenous compounds like NTs, with minimal invasiveness, which is of particular importance for in vivo analysis. Hence, these techniques are very promising and warrant application and further development.