@article{Hang2026, 
author = {Tianxiang Hang and Fubin Pei and Ciyang Zhang and Ming Yang and Mingzhu Xia and Qingli Hao and Wu Lei},
title = {Ultra-long-range hot electron tunneling: Plasmonic nanoengineering enhanced self-powered photoelectrochemical immunoassay},
year = {2026},
journal = {Nano Research},
volume = {19},
number = {3},
pages = {94908357},
keywords = {plasmonic, Z-scheme, ultra-long-range, hot electron tunneling, photoelectrochemical immunoassay},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94908357},
doi = {10.26599/NR.2026.94908357},
abstract = {Constructing ultra-long-range nanogaps for enabling significant plasmonic tunneling phenomena represents a long-standing goal of the research on localized surface plasmon resonance effect. However, such electric field-enhanced tunneling effect is frequently limited by the gap size and band structure configurations between plasmonic nanoparticles and semiconductors. Here, we designed six distinct morphologies of gold nanoparticles and dual Z-scheme substrate with matchable tunneling barriers, which successfully achieved the ultrasensitive PEC immunoassay by utilizing bioconjugates as an ultra-long-range dielectric layer. First, Au stars demonstrated the optimal performances in both finite element method simulations and surface-enhanced Raman spectroscopy experiments among the six gold nanoparticles. Furthermore, the density functional theory calculations and experimental results revealed the dual Z-scheme heterojunction configuration (TiO2@TpPa-2@CdS) as the most efficient substrate for facilitating ultra-long-range hot electron tunneling. The plasmonic tunneling enhanced immunoassay exhibited an ultrasensitive detection of carcinoembryonic antigen (CEA) with the limit of detection as low as 0.012 pg·mL−1. These results provide compelling evidence for ultra-long-range tunneling effect in plasmonic systems, thereby enabling more potential applications in plasmonic technology.}
}