Abstract
Thin films of organic moiety functionalized carbon nanotubes (CNTs) from a very well-dispersed aqueous solution were designed on a screen printed transducer surface through a single step directed assembly methodology. Very high density of CNTs was obtained on the screen printed electrode surface, with the formation of a thin and uniform layer on transducer substrate. Functionalized CNTs were characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) surface area analyzer methodologies, while CNT coated screen printed transducer platform was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed methodology makes use of a minimum amount of CNTs and toxic solvents, and is successfully demonstrated to form thin films over macroscopic areas of screen printed carbon transducer surface. The CNT coated screen printed transducer surface was integrated in the fabrication of electrochemical aptasensors for breast cancer biomarker analysis. This CNT coated platform can be applied to immobilize enzymes, antibodies and DNA in the construction of biosensor for a broad spectrum of applications.
Highlights
Carbon nanomaterials have become the subject of intense research in the last few decades due to their unique structural and physical properties
carbon nanotubes (CNTs) were functionalized by employing diazonium salt chemistry, which resulted in CNTs bearing benzoic acid as an organic moiety, and, subsequently, films were fabricated on carbon electrodes using well-dispersed functionalized CNT aqueous solution. This assembly method offers various potential advantages in the construction of biosensors such as no need of any prior chemical modification of carbon electrode surface, use of water as solvent, one step simple fabrication directly from solution using a very small amount of CNTs and reuse of solution used for thin film assembly
Fourier transform Infrared (FTIR) spectra of multi-walled carbon nanotubes (MWCNTs) and functionalized MWCNTs were recorded using a Thermo Fisher Scientific Nicolet 6700 spectrometer (Waltham, MA, USA), Brunauer–Emmett–Teller (BET) surface area was analyzed by using Micromeritics Tristar II surface and porosity analyzer (GA, USA), Thermogravimetric analysis (TGA) was performed in a TA Instruments SDT Q 600 (New Castle, DE, USA) from 50 to 800 ◦ C under nitrogen atmosphere, X-ray diffraction patterns were recorded using a PANalytical Xpert Powder Diffractometer (Almelo, The Netherlands)
Summary
Carbon nanomaterials have become the subject of intense research in the last few decades due to their unique structural and physical properties. Fabrication of a highly selective monolayer with high density of CNTs in small features with complex shapes on screen printed transducers was expected to provide an ideal platform for on-surface chemistry, and has been demonstrated in this work These modified screen printed carbon electrodes were further exploited to develop a very sensitive electrochemical DNA aptamer-based biosensor to detect mucin (MUC1), a prevalent gene associated with breast cancer [16]. Specific application of the designed surface is demonstrated in the construction of a electrochemical aptasensor, this methodology can be very extended to design other types of bioreceptor surfaces such as those employing enzymes, antibodies, or cells as recognition elements
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
