Optical biosensors for miRNA detection: Lighting the path to cancer diagnosis

Optical biosensors are regarded as the novel and highly efficient tools in cancer diagnosis. They involve the high performance in sensing of several biological biomarkers, and their sensitivity and selectivity properties can provide a more sophisticated and reliable assessment of cancer detection compared to conventional detection methods. Several biomarkers play a crucial role in the early detection of cancers and have been investigated. Among these biomarkers, circulating miRNAs are non-coding endogenous RNAs with ambiguous roles which are found in body fluids. These biomolecules typically have about 19–24 nucleotides in length. The abnormal expression of miRNAs has been demonstrated to be associated with many cancer diseases. Recently, several attempts have been made for the detection of reliable miRNA biomarkers for cancer diagnosis and prognosis. In the present review, we systematically summarize the latest advancements with focuses on optical sensing techniques, including colorimetric, fluorescence, surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS) and paper-based sensors. The review delves into their mechanisms, materials utilized, and strategies for miRNAs detection. • Recent improvements in optical based biosensors have been discussed for detection of miRNAs. • The applied optical biosensors including colorimetric, fluorescence, SPR, SERS and paper-based strategies were described. • We reviewed current application of optical biosensors for cancer early diagnosis and highlight their advantages compared to conventional methods.