Microcantilever-based label-free characterization of temperature-dependent biomolecular affinity binding

Abstract

This paper presents label-free characterization of temperature-dependent biomolecular affinity binding on solid surfaces using a microcantilever-based device. The device consists of a Parylene cantilever one side of which is coated with a gold film and functionalized with molecules as an affinity receptor to a target analyte. The cantilever is located in a poly(dimethylsiloxane) (PDMS) microfluidic chamber that is integrated with a transparent indium tin oxide (ITO) resistive temperature sensor on the underlying substrate. The ITO sensor allows for real-time measurements of the chamber temperature, as well as unobstructed optical access for reflection-based optical detection of the cantilever deflection. To test the temperature-dependent binding between the target and receptor, the temperature of the chamber is maintained at a constant setpoint, while a solution of unlabeled analyte molecules is continuously infused through the chamber. The measured cantilever deflection is used to determine the target-receptor binding characteristics. We demonstrate label-free characterization of temperature-dependent binding kinetics of the platelet-derived growth factor (PDGF) protein with an aptamer receptor. Affinity binding properties including the association and dissociation rate constants as well as equilibrium dissociation constant are obtained, and shown to exhibit significant dependencies on temperature.

Electrochemical Aptamer-Based Sensors with Tunable Detection Range

“…In addition, the sensitivity of a Nanomolar Kanamycin A sensor has been found to be 100 times lower at the temperature of 37 °C than that at room temperature . In addition, the temperature was proven to have an influence on the affinity of some aptamers . For example, aptamers for the detection of Aflatoxin B1 could exhibit a much lowered dissociation constant and greatly enhanced affinity at 4 °C than at 25 °C …”

“…132 In addition, the temperature was proven to have an influence on the affinity of some aptamers. 133 For example, aptamers for the detection of Aflatoxin B1 could exhibit a much lowered dissociation constant and greatly enhanced affinity at 4 °C than at 25 °C. 134 Electrolyte's pH.…”

Soft and flexible material-based affinity sensors

“…Separation and detection of different analytes with high resolution and sensitivity can be achieved by combing these microfluidic platforms and affinity receptors with different transducing elements, such as fluorescence and luminescence-based monitoring (Wu et al, 2016), cantilever vibration (Wang et al, 2013), micro-ring resonators (De Vos et al, 2009) and electrical assays based on impedance (Furniturewalla et al, 2018), conductimetry (Díaz-González et al, 2015) and amperometry (Jang et al, 2006). For instance, Wu et al (Wu et al, 2016) introduced a closed bipolar electrode (BPE)-electrochemiluminescence (ECL) strategy for the detection of specific cancer cells (HL-60 cells), in which a two-channel polydimethylsiloxane (PDMS) chip (sensing channel and reporting channel) was connected through a U-shaped indium tin oxide BPE at a glass surface.…”

Epitope Binning Assay Using an Electron Transfer-Modulated Aptamer Sensor

“…Typically, surface plasmon resonance, − quartz crystal microbalance, − and microcantilever − are widely used in ligand–receptor binding affinity analysis. However, most of these techniques are based on the property alteration of the sensing interface, and the nonspecific adsorption between the interface (not the receptor probe) and target has great influence on the signal response, resulting in low reliability and accuracy.…”