(I-339) Portable impedimetric electrochemical biosensor for diagnosis of Alzheimer’s disease

Introduction:: Alzheimer's disease (AD) is the prevalent type of dementia, affecting approximately 37 million people globally. Without the development of effective therapeutic techniques, this number is projected to rise to 115 million by 2050. Despite there being no cure for Alzheimer's disease, which impacts over 5 million individuals in the United States and approximately 50 million people globally, specialists contend that early detection of the condition remains crucial. Studies indicate that during the onset of neurodegenerative diseases, the immune system displays protective responses and releases neurofilaments (Nfs). Neurofilament-light chain (NfL) is a component of Nfs that could serve as a significant biomarker for various neurodegenerative diseases, and the advancement of these illnesses is related to the quantity of NfL present. This study introduces a new and quick method that uses an electrochemical biosensor to identify NFL protein, among the potential markers to anticipate the onset of Alzheimer's disease (AD).


Materials and Methods:: To create a self-assembled monolayer (SAM), the cross-linker 3,3'-Dithiobis(sulfosuccinimidylpropionate) (DTSSP) (5 mM) was linked to the gold screen printed electrodes through dissociative chemisorption (DTSSP/Au). The DTSSP/Au sensor was then incubated with anti-NFL (20 µg/mL) in PBS for 2 h (anti-NFL/DTSSP/Au). Then BSA (30 mL, 0.1mg/mL) was casted on the electrode for 45 min to block the nonspecific adsorption sites (BSA/SA/DTSSP/ Au). Finally, the electrode was incubated with different concentrations of antigen-NFL for 60 min and the NFL antigen-modified electrochemical biosensor has been prepared

Results, Conclusions, and Discussions:: The preliminary analysis of the screen-printed gold electrodes has confirmed their appropriateness for the fabrication of electrochemical impedance sensors. By generating impedance signals that demonstrate the efficacy of our manufacturing method for gold-based electrodes, we have demonstrated a proof-of-concept. Figure 1 illustrates that as the fabrication process progresses, specifically with the inclusion of DTSSP, there is a growth in the impedance signal.

A label-free electrochemical immunosensor is developed for the purpose of detecting NfL, which is shown to be an informative biomarker for a number of neurological disorders. In the future, we plan to shift our fabrication process to more flexible materials and replace the capture probe with anti-spike protein antibodies. This transition is feasible due to the platform's modularity, which also enables us to efficiently create sensors for other biomarkers.

Acknowledgements (Optional): : We would like to acknowledge the Human Open Research Neural Engineering Technologies (HORNET) grant.

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