# Inkjet-Printed Electrode Enable Portable Electrochemical Immunosensing of Tau-441 for Early Alzheimer’s Screening

## TL;DR

A portable device using inkjet-printed electrodes can detect a key Alzheimer’s biomarker at very low levels, enabling early screening.

## Contribution

A scalable and portable electrochemical immunosensing method for Tau-441 detection using inkjet-printed electrodes and gold nanoparticles.

## Key findings

- The method achieves a detection limit of 16 fg/mL for Tau-441 with high specificity and reproducibility.
- The system provides a linear response from 50 fg/mL to 10 ng/mL of Tau-441.
- The integration of inkjet printing and a handheld reader enables rapid and on-site Alzheimer’s screening.

## Abstract

Early diagnosis of Alzheimer’s disease represents a critical clinical challenge, and the high-sensitive biomarkers measurement holds great potential for enabling early identification and intervention. This study proposes an electrochemical immunosensing strategy based on inkjet printing for the quantitative detection of Tau-441. Conductive patterns were formed by inkjet printing, followed by surface functionalization with gold nanoparticles to immobilize highly specific anti-Tau-441. This process created a stable and high affinity immunorecognition interface that enhances electron transfer and signal amplification. Furthermore, we developed and integrated a low-power portable detection platform to achieve a rapid detection process encompassing sample loading, signal acquisition, and on-device readout. The method shows a linear response from 50 fg/mL to 10 ng/mL and a limit of detection of 16 fg/mL (S/N = 3), with high specificity and good reproducibility. By combining scalable inkjet fabrication with a self-contained handheld reader, this method shortens the path from sample to result and offers a practical route for on-site screening and early intervention in Alzheimer’s disease.