TY  - JOUR
AU  - Hang, Tianxiang
AU  - Pei, Fubin
AU  - Zhang, Ciyang
AU  - Yang, Ming
AU  - Xia, Mingzhu
AU  - Hao, Qingli
AU  - Lei, Wu
PY  - 2026
TI  - Ultra-long-range hot electron tunneling: Plasmonic nanoengineering enhanced self-powered photoelectrochemical immunoassay
JO  - Nano Research
SN  - 1998-0124
SP  - 94908357
VL  - 19
IS  - 3
AB  - 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.
UR  - https://doi.org/10.26599/NR.2026.94908357
DO  - 10.26599/NR.2026.94908357