Polish title: Elektroanaliza związków o znaczeniu neurobiologicznym
Funding source: National Science Centre Poland (NCN)
Project number: 2020/39/D/ST4/02256
PI: Emilia Witkowska Nery
Total funding: 1 580 800,00 PLN
Timeframe: 01/10/2021 -30/09/2024
This project’s primary scientific goal is to understand and describe the processes of adsorption and transfer of ions and molecules across liquid-liquid interfaces and how the information provided in such systems can complement the one obtained through traditional electrochemical means based on a solid-liquid interface. As model molecules, which will allow a better understanding of such systems, we choose neurobiologically relevant analytes: matrix metallopeptidase 9 (MMP-9) and neurotransmitters. Although dopamine is the first and most often analyzed neurotransmitter detected by electrochemical means, regardless of the effort made for simultaneous detection of dopamine and serotonin, no reliable method was proposed. In the case of MMP-9, the main problem of the available electrochemical sensors is their mode of action based on peptide cleavage, which does not allow constant detection. After the peptide is cleaved, the sensor is considered consumed.
Traditional voltammetric techniques quantify the exchange of electrons between the molecule of interest and the electrode but in the case of ion-transfer voltammetry, the molecule does not have to be electroactive. The prerequisite for the detection is the charge of the molecule. Because of this, ion-transfer voltammetry became an exciting means to electrochemically analyze non-electroactive molecules such as proteins.
Although studies of transfer and adsorption of proteins at the electrified interface include glucose oxidase, hemoglobin, lysozyme, albumin, they are mainly done in highly acidic model solutions and provide little understanding on the transfer of such molecules in their still charged but native state. One of the fundamental questions that we will address in the current project is ion-transfer voltammetry’s ability to detect different conformations of proteins and if such technique could potentially serve as a method of constant detection of MMP-9 in neuronal cultures.
The main hurdle in simultaneous analysis of dopamine and serotonin is not only their similar detection potential, which requires the employment of electrode modification strategies but also the polymerization of dopamine at physiological pH, which causes inactivation of the sensor. Given the considerable effort of the scientific community to solve this problem the proposed strategy will be twofold. First, sensors will be fabricated from double barrel capillaries to allow both modes of detection, at one side through ion-transfer voltammetry, at the other, using well-established methods of voltammetric analysis of dopamine on carbon. Secondly, machine learning methods will be applied to quantify both compounds based on multivariate curve resolution or multivariate regression. Exploratory data analysis will also be used to obtain a better understanding of which information from each of the sensing strategies allows for simultaneous detection.