Microfluidic device for one-step detection of breast cancer-derived exosomal mRNA in blood using signal-amplifiable 3D nanostructure

Abstract

Metastasis attributed to approximately 90% of cancer-related deaths; hence, the detection of metastatic tumor–derived components in the blood assists in determining cancer recurrence and patient survival. Microfluidic–based sensors facilitate analysis of small fluid volumes and represent an accurate, rapid, and user-friendly method of field diagnoses. In this study, we have developed a microfluidic chip-based exosomal mRNA sensor (exoNA-sensing chip) for the one-step detection of exosomal ERBB2 in the blood by integrating a microfluidic chip and 3D-nanostructured hydrogels. The exoNA-sensing chip is a vacuum-driven power-free microfluidic chip that can accurately control the flow of trace fluids (<100 μL). The sensing part of the exoNA-sensing chip includes 3D-nanostructured hydrogels capable of detecting ERBB2 and a reference gene by amplifying a fluorescent signal via an enzyme-free catalytic hairpin assembly reaction at room temperature. This hydrogel offers a detection limit of 58.3 fM with good selectivity for target sequences. The performance of the exoNA-sensing chip was evaluated by testing in vitro and in vivo samples and was proven to be effective for cancer diagnosis and liquid biopsies.