Chemically Self-Assembled\nMonolayer Semiconducting\nSingle-Walled Carbon Nanotube-Based Biosensor Platform for Amyloid‑β\nDetection

This paper presents a platform for amyloid-β (Aβ)\nbiosensors,\nemploying nearly monolayer semiconducting single-walled carbon nanotubes\n(sc-SWNTs) via click reaction. A high-purity sc-SWNT ink was obtained\nby employing a conjugated polymer wrapping method with the addition\nof silica gel. Aβ detection involved monitoring the electrical\nresistances of the sc-SWNT layers. Electrical resistances increased\nrapidly corresponding to the concentration of amyloid-β 1–42\n(Aβ1–42) peptides. Furthermore, we introduced Aβ\npeptides onto the 1-pyrenebutanoic acid succinimidyl ester (PBASE)\nlinker, confirming that only the chemical adsorption of the peptide\nby the antibody–antigen reaction yielded a significant change\nin electrical resistance. The optimized sensor exhibited a high sensitivity\nof 29% for Aβ at a concentration of 10 pM. Notably, the biosensor\nplatform featuring chemically immobilized sc-SWNT networks can be\ncustomized by incorporating various bioreceptors beyond Aβ antibodies.