Carrier dynamics modulation in Au/end-CeO2 dumbbell heterojunctions for sensitive photothermal lateral flow assays

Rapid, synchronous, and quantitative detection of interleukin-6 (IL-6) and procalcitonin (PCT) is of great significance for the early diagnosis of infectious diseases, yet it remains a formidable challenge for conventional lateral flow immunoassays (LFIAs) due to their inherent semi-quantitative nature and limited sensitivity. Herein, we tackle this challenge through the rational design of dumbbell-shaped Au/end-CeO 2 heterojunctions, where the site-specific deposition of CeO 2 on gold nanorods creates a Schottky interface that profoundly modulates carrier dynamics. This unique architecture effectively suppresses electron-hole recombination and enhances localized electromagnetic fields, yielding an exceptional photothermal conversion efficiency of 58.22%—a 39.3% increase over pure Au nanorods. Capitalizing on this advanced nanomaterial, we engineer a colorimetric/photothermal dual-mode LFIA platform. This platform not only achieves ultrasensitive individual detection of IL-6 and PCT with detection limits as low as 44 and 52 pg·mL −1 , respectively, but also realizes their efficient synchronous co-detection in a single, rapid chromatography step. By integrating visual colorimetric screening with quantitative photothermal readout, this work establishes a material foundation and technical pathway toward highly sensitive, quantitative LFIA systems, providing a referential approach for rapid screening in settings where access to large-scale instrumentation is limited.