Label‐Free Electrochemical Microfluidic Sensing Platform for the Detection of <i>miR‐30b</i> from Milk Samples

Circulating microRNAs (miRNAs) in biological fluids are small non‐coding RNAs identified as promising biomarkers. They are particularly abundant in milk, a fluid easily accessible without invasive techniques. However, detection methods are currently performed by specialized personnel in centralized laboratories, which greatly lengthen analysis times. This study addresses some challenges by proposing a portable microfluidic electrochemical platform for the detection of miR‐30b , a miRNA overexpressed by a previously developed transgenic mouse model. The sensors integrated into the platform were surface‐modified with oligonucleotides. Through dual‐mode detection by cyclic voltammetry and electrochemical impedance spectroscopy, they exhibit high specificity and sensitivity with a detection range from 10 −16 to 10 −8 M. Tests on real samples show that the platform is able to distinguish between miR‐30b extracted from milk of transgenic mice and that of wild‐type mice. These results suggest a strong potential of this sensing platform to carry out early and noninvasive detections. They open the way to precise monitoring of the physiological state of individuals while improving diagnostic options for pathologies in clinical or veterinary settings.