An electrochemical biosensor integrating self-propelled nanocarriers with DNA cascade amplification strategy for ultrasensitive PPIA detection.
TL;DR
An electrochemical biosensor that integrates self-propelled nanocarriers with DNA cascade amplification strategy for ultrasensitive PPIA detection and exhibits excellent specificity and performs reliably in clinical lung adenocarcinoma serum specimens, demonstrating its promising applicability for early diagnosis of this malignancy.
Abstract
Peptidylprolyl isomerase A (PPIA) catalyzes cis-trans isomerization of proline residues, a key process regulating protein folding and signal transduction. Its aberrant secretion is closely associated with tumor metastasis and progression, making it a promising biomarker. However, currently available immunoassays often suffer from insufficient sensitivity for low-abundance PPIA detection. Herein, we present an electrochemical biosensor that integrates self-propelled nanocarriers with DNA cascade amplification strategy for ultrasensitive PPIA detection. The biosensor employs PtNPs@COF particles that catalyze H2O2 decomposition to generate O2. This autonomous propulsion accelerates target binding in homogeneous solution and helps mitigate diffusion-limited binding kinetics. After PPIA binding, the liberated DNAzyme catalytically cleaves the co-immobilized substrate strands, generating numerous triggers for the catalytic hairpin assembly (CHA) reaction. The biosensor achieves a wide linear range from 1 pg/mL to 10 μg/mL with a detection limit of 0.330 pg/mL. It also exhibits excellent specificity and performs reliably in clinical lung adenocarcinoma serum specimens, demonstrating its promising applicability for early diagnosis of this malignancy.