Ultrasensitive MXene Biosensor for Label-Free miRNA Detection

An extremely sensitive MXene-enhanced plasmonic biosensor for real-time and label-free detection of microRNAs (miRNAs) has been proposed by a research group at the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences, under the direction of Prof. Hui Yang.

Micro RNA (miRNA) 3d illustration

Image Credit: ART-ur/

Nanophotonics published the findings on October 11th, 2023.

miRNAs, which are small non-coding RNA molecules, are involved in the initiation and spread of many cancer types. Since miRNAs can function as biomarkers, their discovery is important for early-stage diagnoses and prognostics.

However, standard detection methodologies for miRNAs confront difficulties because of their intrinsic properties, which include small size, short sequence length, low concentration levels, and high sequence homology in complicated actual samples.

The researchers in this study discovered that spin-coating a small layer of MXene nanosheets on the plasmonic substrate could significantly decrease its reflectivity, leading to an abrupt phase change at the surface plasmon resonance angle. Consequently, a significant lateral displacement signal would be induced by the abrupt phase change, increasing the sensitivity of the detection.

The researchers achieved ultrasensitive target miRNA detection with a detection limit as low as 10 fM using this biosensing technique. The target miRNA could be easily distinguished from the single-base mismatched miRNA, thanks to the sensing signal.

Moreover, this plasmonic biosensor shows that it can identify miRNAs in complicated media without sacrificing detection sensitivity, such as undiluted human serum samples.

Our biosensing technique provides a promising tool for effective detection of miRNA. It can evolve into a platform to detect a wide class of nano-objects, such as many other tumor biomarkers in clinical diagnosis and viral particles.

Hui Yang, Professor, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences

Journal Reference:

Wang, Y., et al. (2023) Ultrasensitive label-free miRNA-21 detection based on MXene-enhanced plasmonic lateral displacement measurement. Nanophotonics. doi:10.1515/nanoph-2023-0432