16Ch BDD-MEA devices: solid tools for the amperometric determination of serotonin released by exocytosis in human platelets

Introduction.

Amperometry is an electrochemical technique that allows the release of oxidizable amines by exocytosis to be studied. Serotonin is a neurotransmitter involved in the control and regulation of motor activity, body temperature, appetite, perception, cognitive function, sexual appetite, emotions and mood. It is important to know how serotonin is released directly in human cells.

Methods.

We used novel boron-doped diamond 16-microelectrode array devices (“16Ch BDD-MEA”)^1,2 to carry out amperometric measurements of serotonin release by exocytosis from human platelets. These cells store 90% of the blood serotonin. They are an easy cell model obtained from blood samples. We studied serotonin exocytosis in two different types of “16Ch BDD-MEA” devices: opaque on silicon substrates and transparent on quartz substrates.^1,2

Results.

We detected the exocytosis of serotonin as typical positive deflections called secretory spikes. From these spikes, we could extract kinetics parameters such as Imax (maximum oxidation current, in pA), t_1/2 (spike width at half maximum, in ms), Q (quantum size or spike net charge, in pC) and ascending slope of spike (in pA/ms). Studies were carried out under basal conditions and after loading the platelets with 10 µM serotonin for 2 h to explore the uptake mechanisms.^1,2

Conclusions.

“16Ch BDD-MEA” systems are an effective tool for quantitatively studying exocytosis of neurotransmitter serotonin from human platelets.

References.

¹ González Brito et al., Biosensors 2023, 13, 86.
² González Brito et al., R. Biosensors 2024, 14, 75.