An integrative and efficient microbiosensor for β-amyloid42 based on a molecularly imprinted layer coordinating built-in hemin on the acupuncture needle

Monitoring beta-amyloid_1–42 (Aβ₄₂) is vital and challenging, which is a typical biomarker of Alzheimer's disease. Here, a novel electrochemical microbiosensor is developed to detect Aβ₄₂ on an acupuncture needle. Hemin is well known for its characteristics, including its ability to self-assemble on single-walled carbon nanotube (SWCNT), the molecular interaction with Aβ₄₂, and the intrinsic electroactive signal. These properties are exploited to anchor and respond to Aβ₄₂ after integrating a molecularly imprinted surface polymer (SMIP). The SMIP layer of polydopamine/poly (ionic liquid) can be prepared by electropolymerization on an acupuncture needle microelectrode (ANME), which undergoes growth and formation of a polymeric structure around the anchored Aβ₄₂. Interestingly, the imprinted cavities express a fluent signal of built-in hemin after eluting the templates, and show a highly selective and sensitive hindrance response for the recombined Aβ₄₂. Under optimized conditions, the microbiosensor displays a linear range of 100 to 1 × 10¹⁰ fM with a limit of detection of 0.05 fM. There are development and advances for the discipline of electroanalysis after comparing the technique and important indicators with the electrochemical biosensors reported of Aβ₄₂. The microbiosensor also exhibited excellent selectivity, good stability, and reproducibility, which was effectively used to detect Aβ₄₂ in real spiked samples. The improved behavior of the developed microbiosensor can be attributed to its superficial highly matched imprinted cavities, built-in hemin label, and electronic barrier without signal of the nonimprinted surface to outside molecules. This microbiosensor has a scientific and reference value for directly sensing non-electroactive biomarkers, functionalizing microelectrodes, and electron transport cavities. It would also be amazing if this new microbiosensor could combine with the unclear and magical property of acupuncture in the treatment of neurological disorders.