Lu Haoliang, Samman Fatimah, Hasan Erol, Alsulaiman Dana
Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
Material Science and Engineering Program Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
Small. 2025 Aug;21(33):e2503990. doi: 10.1002/smll.202503990. Epub 2025 Jun 25.
Robust and ultrasensitive biosensing platforms for detecting clinically relevant biomarkers from liquid biopsies are vital for precision diagnostics. However, detecting low-abundance biomarkers such as microRNA typically necessitates complex and costly enzyme-based strategies like PCR or isothermal amplification. Here, a materials-driven approach is leveraged to rationally design stimuli-responsive, signal-amplifying, and graphically-encoded hydrogel microparticles, termed Novabeads, for enzyme-free and fluorescence-based biomarker detection. Novabeads incorporate pH-responsive acrylic acid moieties within a polyethylene glycol diacrylate-based network, enabling significant volume reduction (≈5 fold) upon pH modulation. This stimuli-responsive shrinking, coupled with high bioreceptor loading via thiol-ene click chemistry, enables rapid, enzyme-free optical signal amplification. As a proof-of-concept, fluorescently-labeled peptide nucleic acid (PNA) probes are designed for detecting the cancer biomarker miR-16, via a fluorogenic Förster resonance energy transfer (FRET)-based signal. Novabeads exhibit >30 fold signal enhancement over equivalent conventional hydrogel microparticles, driven by three synergistic mechanisms: increased probe loading (≈2.6 fold), enhanced target capture (≈2.8 fold), and shrinkage-driven amplification (≈5 fold), ultimately leading to over 7 fold reduction in detection limit (28.8 pM; 2.9 fmol), and an expanded linear dynamic range. This rationally designed materials-driven biosensing strategy enables next-generation robust, versatile and enzyme-free biosensors for liquid biopsy diagnostics.
用于从液体活检中检测临床相关生物标志物的强大且超灵敏的生物传感平台对于精准诊断至关重要。然而，检测低丰度生物标志物（如微小RNA）通常需要复杂且昂贵的基于酶的策略，如PCR或等温扩增。在此，利用一种材料驱动的方法合理设计了刺激响应、信号放大和图形编码的水凝胶微粒，称为Novabeads，用于无酶且基于荧光的生物标志物检测。Novabeads在聚乙二醇二丙烯酸酯基网络中引入了pH响应性丙烯酸基团，在pH调节时可实现显著的体积减小（约5倍）。这种刺激响应性收缩，再加上通过硫醇-烯点击化学实现的高生物受体负载，能够实现快速、无酶的光信号放大。作为概念验证，设计了荧光标记的肽核酸（PNA）探针，通过基于荧光共振能量转移（FRET）的信号来检测癌症生物标志物miR-16。Novabeads比同等的传统水凝胶微粒表现出超过30倍的信号增强，这是由三种协同机制驱动的：探针负载增加（约2.6倍）、靶标捕获增强（约2.8倍）和收缩驱动的放大（约5倍），最终导致检测限降低超过7倍（28.8 pM；2.9 fmol），并扩大了线性动态范围。这种合理设计的材料驱动的生物传感策略为液体活检诊断带来了下一代强大、通用且无酶的生物传感器。
