Sensing of Digestive Proteins in Saliva with a Molecularly Imprinted Poly(ethylene-co-vinyl alcohol) Thin Film Coated Quartz Crystal Microbalance Sensor

Abstract

The quartz crystal microbalance (QCM) has a sensitivity comparable to that of the surface plasmon resonance (SPR) transducer. Molecularly imprinted polymers (MIPs) have a much lower cost than natural antibodies, they are easier to fabricate and more stable, and they exhibit satisfactory recognition ability when integrated onto sensing transducers. Hence, MIP-based QCM sensors have been used to recognize small molecules and, recently, microorganisms, but only a few have been adopted in protein sensing. In this work, a mixed salivary protein and poly(ethylene-co-vinyl alcohol), EVAL, solution is coated onto a QCM chip and a molecularly imprinted EVAL thin film formed by thermally induced phase separation (TIPS). The optimal ethylene mole ratios of the commercially available EVALs for the imprinting of amylase, lipase and lysozyme were found to be 32, 38, and 44 mol %, respectively. Finally, the salivary protein-imprinted EVAL-based QCM sensors were used to detect amylase, lipase and lysozyme in real samples (saliva) and their effectiveness was compared with that of a commercial ARCHITECT ci 8200 chemical analysis system. The limits of detection (LOD) for those salivary proteins were as low as ∼pM.

Molecular Imprinting Technology in Quartz Crystal Microbalance (QCM) Sensors

“…In a study reported by Lee et al [37] MIP film-coated QCM sensors were used for the selective recognition of lipase, amylase and lysozyme which are digestive enzymes found in saliva. For this purpose, the sensor surface was coated with a mixture of target protein and poly(ethylene-co-vinyl alcohol).…”

Molecularly imprinted electrochemical sensing of urinary melatonin in a microfluidic system

“…%. 24 C. The evaluation of the melatonin-imprinted EVAL coated electrodes for the determination of melatonin in human urine samples…”

Microfluidic Electrolyzers for Production and Separation of Hydrogen from Sea Water using Naturally Abundant Solar Energy

“…[2,3] Ah ost of such process-intensifiedc ommercial technologies are now available for processest hat involve high-throughput reaction engineering, [4] the synthesis of essential organic and inorganic materials, [3,[5][6][7] the preparation of biomedical products, [8,9] and the manufacture of explosives [10] and pharmaceutical products. [11] Microfluidicr eactors also play ap ivotal role to revolutionize the products and processes in research areas associated with self-assembled monolayers, [12,13] sensors, [14][15][16] biomedical devices, [17,18] cancer research, [19] lab-on-a-CD devices, [20] microelectronic chips, [21] and particles ynthesis. [22] Thus,i ti sn ot surprising that the design [23][24][25] and development of microreactors [26,27] that have attributes either similar to or superior to their macroscopic counterpartsh ave now become one of the most competitive areas of research.…”