Interfacial nano-biosensing in microfluidic droplets (Image credit: Dr. James XiuJun Li, UT) 

Many organic molecules (e.g. estradiol) often have detection problems due to low-solubility issues in aqueous solutions.  A team led by Dr. XiuJun Li at the University of Texas at El Paso (UTEP) in Texas, USA has developed an innovative interfacial nano-biosensing strategy in microfluidic droplets for high-sensitivity one-step detection of low-solubility molecules. This work has been recently published in Chem Comm 2016, 52, 4370.

A droplet microfluidic system for one-step estradiol detection using aptamer-functionalized GO nanosensors. The high surface-to-volume ratio from droplet microfluidics enables high-sensitivity interfacial nano-biosensing. (Image credit: XiuJun Li et al., ChemComm 2016) 

Taking advantage of the high surface-area-to-volume ratio property of microfluidic droplets, the interfacial nano-biosensing strategy based on aptamer-functionalized graphene oxide nanosensors in microfluidic droplets can achieve high-sensitivity and one-step detection of 17β-estradiol and other low-solubility molecules. The limit of detection for 17β-estradiol was reported to be as low as 0.07 pM by using their interfacial nano-biosensing strategy, which was improved by about 3 orders of magnitude than conventional detection systems. It is expected that the Li Group’s study should have great potential for high-sensitivity environmental and food safety monitoring. In addition, their study also demonstrates an efficient strategy to solve the detection problems of many low-solubility compounds (e.g. a number of hormones, proteins, drugs, vitamins, fats, polymers and other organic compounds) in numerous aqueous solutions-based detection systems.