Real-time and selective recognition of erythromycin by self-assembly of calix[4]arene on QCM sensor

Abstract

This paper describes the synthesis of an amino morpholine-based the new schiff base calix[4]arene (compound 5), it's coating on Quartz Crystal Microbalance (QCM) crystal as a self-assembled monolayer (SAM), and real-time detection of erythromycin (ERY) in aqueous media. The characterization of the QCM sensor has been succeeded with atomic force microscopy and contact angle measurements. Initial experiments revealed that the frequency response decreased quickly as expected and reached equilibrium within 5 min which means that there was a good interaction between the compound 5 coated QCM sensor surface and ERY molecules. The QCM sensor showed a linear response towards ERY solutions in different concentrations ranging from 10 to 200 μM, with the sensitivity (S) and limit of detection (LOD) being 0.66 Hz/μM and 4.80 μM, respectively. Furthermore, the adsorption behavior and mechanism of ERY onto the QCM sensor were applied for this sensing system and the adsorption data exhibited a good correlation with the Langmuir adsorption isotherm in terms of R2 and Δmmax. The QCM sensor was shown outstanding selective performance to ERY among some biologic molecules such as amino acid, drug, hormone, vitamin. Thus, real-time, sensitive, selective and effective recognition of ERY was performed by a calixarene derivative coated QCM sensor.