A Tailored Self-Assembling Monolayer for Monitoring Biomarkers in Cell Culture Media Using the liSPR System
|Anja Henseleit*, Natalie Haustein, Carolin Pohl, Thomas Bley and Elke Boschke|
|Technische Universität Dresden, Institute of Food Technology and Bioprocess Engineering, 01062 Dresden, Germany|
|Corresponding Author :||Anja Henseleit
Technische Universität Dresden
Institute of Food Technology and Bioprocess Engineering
01062 Dresden, Germany
Tel: +49 0351 46334272
Fax: +49 0351 46337761
E-mail: [email protected]
|Received: November 13, 2015; Accepted: November 28, 2015; Published: December 9, 2015|
|Citation: Henseleit A, Haustein N, Pohl C, Bley T, Boschke E (2015) A Tailored Self-Assembling Monolayer for Monitoring Biomarkers in Cell Culture Media Using theliSPR System. J Biochip Tissue 5:112. doi:10.4172/2153-0777.1000112|
|Copyright: © 2015 Henseleit A, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
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Surface plasmon resonance (SPR) spectroscopy is a promising chip-based biosensor technology that can quantify various biomarkers without molecular labels or time-consuming sample preparation. The liSPR spectrometer is an inexpensive, convenient, portable, and robust SPR system. A drawback is that the chips’ sensing surfaces are fragile as they consist of a thin layer of gold sputtered directly on a polymer slide, without the Cr or Ti adhesive layers typically used in other SPR chips. Furthermore, interfering substances, particularly non-target proteins, may adsorb to the gold due to its hydrophobicity. This can lead to non-specific sensor signals or even inactivation of the ligands and hence false SPR signals. Thus, to improve the system’s reliability the bare gold surface must be modified.
Here, we present a tailored sensor surface for measuring human serum albumin (HSA) levels of human hepatocytes cultivated in vitro in media containing huge numbers of proteins capable of adsorbing to a bare gold surface. The key feature is a mixed self-assembled monolayer (SAM) comprising two types of alkanethiols: one for covalently attaching ligand molecules – here antibodies – to the chip and one for suppressing non-specific adsorption of interfering sample components. In addition to describing the new sensor surface we present data on its levels of immobilized antibody, non-specific adsorption of cell culture components, and HSA binding capacities. Calibration curves (obtained using HSA-spiked media samples) are also presented showing that the rapid, convenient sensor system provides similar sensitivity and reliability to standard ELISA methodology.