Microfluidic systems using localized molecular imprinting polymers for detection of nano-scale bio-molecules based on surface plasmon resonance

This paper reports a new microfluidic system integrated with localized molecular imprinting polymers (MIP) for detection of nano-scale bio-molecules based on surface plasmon resonance (SPR). The label-free bio-sensing method incorporates SPR biosensing and an innovative microfluidic biochip capable of transporting a specific amount of bio-samples inside multiple microchannels using micropumps to sensing regions where multiple MIP films are locally spun-coated such that highly-sensitive, high-throughput, and highly-specific bio-sensing of nano-scale biomolecules could be achieved. The microfluidic SPR/MIP biochips have the potential to be widely used for nano biosensing applications. While compared to large-scale SPR techniques, the developed microfluidic system has a comparable sensitivity with less consumption of samples and can perform the sensing in an automatic format.

I. INTRODUCTION

The molecular imprinting polymer (MIP) technology exploits the complex bonding among templates, functional monomers, and cross-linker to form specific detection cavities which have specific and well-orientated functional groups complementary to these template molecules. These artificial molecular sites have the ability of the molecular recognition. The advantages of the MIP technology include high specificity, low-cost, robustness, stable, and easy to preserve. Previous studies have successfully demonstrated that highly specific MIP films could be achieved [1]. Typically, MIP was fabricated in bulk forms and detected by utilizing quartz crystal microbalance (QCM) [1] or high performance liquid chromatography (HPLC). In this work, we used enabling microfluidic technologies to fabricate a new microfluidic system integrating micropumps and microvalves to automate the transportation of bio-samples. A new “localized MIP” technique was also demonstrated to deposit several different MIP films inside multiple microchannels to sense multiple bio-samples. SPR is known to have a high sensitivity based on affinity-based bio-sensing [2]. The advantages of SPR biosensors include, not limited to, labeling-free, high sensitivity, capability of high-throughput quantitative analysis in realtime fashion. However, a large-scale pumping system is usually required. This study thus reports a new microfluidic system integrated with localized molecular imprinting polymers for detection of multiple nano-scale bio-molecules based on surface plasmon resonance.