Active nanorobotic systems for blood-based detection of cancer biomarkers: from passive nanosensors to dynamic liquid biopsy platforms

Abstract

Early and accurate detection of biomarkers in blood remains one of the greatest challenges in precision oncology. Conventional liquid biopsy platforms, including microfluidic devices, affinity capture systems, and nanoparticle-based sensors, have achieved impressive sensitivity but are fundamentally constrained by passive diffusion and limited sampling efficiency. Recent advances in nanorobotics are redefining this diagnostic paradigm by introducing active nanosystems capable of autonomous motion, targeted navigation, and real-time biosensing in complex biological fluids. These active nanorobotic platforms, inspired by biological microswimmers, integrate controlled propulsion, molecular recognition, and multimodal sensing to actively interrogate the circulatory system rather than passively sampling it. By overcoming diffusion limitations and increasing the probability of biomarker encounter, nanorobots offer the potential for continuous, in situ monitoring of disease progression and therapeutic response. Herein, we critically examine the current state of nanorobotic systems for blood-based cancer diagnostics, highlighting advances in actuation mechanisms, biomolecular recognition strategies, and multimodal signal transduction.