Minimally Invasive Real-Time Monitoring for Rapid and Sensitive Diagnosis of Spinal Cord Injury

Spinal cord injury (SCI) is a serious neurological injury that is currently extremely difficult to cure clinically. SCI involves numerous pathophysiological processes, and microRNAs (miRNAs) play an important role in these processes. Meanwhile, miRNAs have received a lot of attention for their role in other diseases as well. Therefore, the detection of disease-related miRNAs is important for the study of disease development, treatment, and prognosis. With the rapid development of molecular biology, the traditional detection methods of miRNA can no longer meet the needs of experiments. Electrochemical detection methods are widely used because of their excellent detection performance. Here, we designed an electrochemical sensor prepared using borosilicate glass microneedle electrodes for real-time monitoring of miR-21-5p expression in vivo after SCI. The sensor showed a good linear relationship between the oxidation peak current value and the concentration of miR-21-5p in the concentration range 0-2 fM (<i>Y</i> = 12.025<i>X</i> + 90.396, <i>R</i>² = 0.98). The limit of detection (LOD) of the sensor was 0.3667 fM. The experimental results showed that the borosilicate glass microneedle electrochemical sensor achieved fast, accurate, highly sensitive, highly specific, highly stable, and reproducible monitoring of miR-21-5p. More importantly, the electrochemical sensor has a better clinical translation prospect, which is important for the research of clinical diseases.