近日，美国华盛顿大学Yang, Lan团队报道了通过光声特征检测和分类自由流动纳米颗粒和细胞的低语走廊模式谐振器。相关论文于2025年12月11日发表在《光：科学与应用》杂志上。

微纳尺度粒子在生物医学成像、环境监测及早期疾病诊断等众多领域具有关键作用，深刻影响着科学研究与工业应用进程。这些粒子的独特性质要求实现精确的检测、表征与识别。然而，传统用于微纳物体表征的光谱与显微技术通常依赖大型设备及复杂耗时的样品制备流程。过去二十年间，光学微传感器以其高灵敏度和紧凑结构成为一种极具前景的传感技术，但其广泛应用受限于选择性传感所需的表面结合要求，以及难以区分不同传感目标的问题，这限制了其在原始状态或复杂生物样本检测中的应用。发展无需标记与固定的传感技术，实现对复杂溶液中目标粒子的直接检测，对突破现有生物传感器的固有局限至关重要。

研究组设计并展示了一种光流体高通量超灵敏光学微谐振器传感器，该器件能够捕获由脉冲光能吸收产生的微弱声信号——微纳粒子在吸收脉冲光能后会产生特征声信号，从而为扩展传感体积内原始溶液环境中的粒子与细胞提供实时、无标记的光声光谱检测与表征。

基于目标物独特的光吸收特性，该技术能够在无需表面结合的情况下，对流过传感系统的粒子进行选择性检测与分类，即使在如全血样本等复杂基质中也能实现。研究组展示了在存在其他细胞成分及多种蛋白质的情况下，对不同几何构型的金纳米粒子及多种红细胞的检测能力。这些粒子通过其光声指纹——包含粒子形状、组成、分子特性与形态特征等信息——实现了有效识别与分类。这项研究为临床与工业应用中实现快速、可靠、高通量的粒子与细胞识别开辟了新途径，为理解复杂生物与环境系统提供了重要工具。

附：英文原文

Title: Whispering-gallery-mode resonators for detection and classification of free-flowing nanoparticles and cells through photoacoustic signatures

Author: Liao, Jie, Adolphson, Maxwell, Li, Hangyue, Sikder, Dipayon Kumar, Lu, Chenyang, Yang, Lan

Issue&Volume: 2025-12-11

Abstract: Micro and nanoscale particles have played crucial roles across diverse fields, from biomedical imaging and environmental processes to early disease diagnosis, influencing numerous scientific research and industrial applications. Their unique characteristics demand accurate detection, characterization, and identification. However, conventional spectroscopy and microscopy commonly used to characterize and identify tiny objects often involve bulky equipment and intricate, time-consuming sample preparation. Over the past two decades, optical micro-sensors have emerged as a promising sensor technology with their high sensitivity and compact configuration. However, their broad applicability is constrained by the requirement of surface binding for selective sensing and the difficulty in differentiating between various sensing targets, which limits their application in detecting targets in their native state or in complex biological samples. Developing label-free and immobilization-free sensing techniques that can directly detect target particles in complex solutions is crucial for overcoming the inherent limitations of current biosensors. In this study, we design and demonstrate an optofluidic, high throughput, ultra-sensitive optical microresonator sensor that can capture subtle acoustic signals, generated by tiny particles from the absorption of pulsed light energy, providing photoacoustic spectroscopy information for real-time, label-free detection and interrogation of particles and cells in their native solution environments across an extended sensing volume. Leveraging unique optical absorption of the targets, our technique can selectively detect and classify particles flowing through the sensor systems without the need for surface binding, even in a complex sample matrix, such as whole blood samples. We showcase the measurement of gold nanoparticles with diverse geometries and different species of red blood cells in the presence of other cellular elements and a wide variety of proteins. These particles are effectively identified and classified based on their photoacoustic fingerprint that captures particle shape, composition, molecule properties, and morphology features. This work opens up new avenues to achieve rapid, reliable, and high-throughput particle and cell identification in clinical and industrial applications, offering a valuable tool for understanding complex biological and environmental systems.

DOI: 10.1038/s41377-025-01978-9

Source: https://www.nature.com/articles/s41377-025-01978-9