Interdigitated Electrode Biosensor Based on Plasma-Deposited TiO2 Nanoparticles for Detecting DNA

Abstract

Bioelectrodes mediated by metal oxide nanoparticles have facilitated the development of new sensors in medical diagnosis. High-purity TiO2 nanoparticles (NPs) were synthesized through thermal plasma and deposited directly on an interdigitated electrode. The surface of the TiO2-deposited electrode was activated with (3-aminopropyl) triethoxysilane (APTES) followed by fixing the single-stranded probe deoxyribonucleic acid (DNA) to fabricate the DNA biosensor. The structural properties of the deposited TiO2 nanoparticles were analyzed using a transmission electron microscope (TEM), X-ray diffraction (XRD), and a dynamic light scattering (DLS) system. The chemical composition and structural properties of the TiO2 nanoparticle layer and the fixed layer were analyzed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). E. coli O157:H7, a well-known pernicious pathogenic bacterial species, was detected as a target DNA of the prepared DNA biosensor, and the characteristics of DNA detection were determined by the current change using a picoammeter. The degree of binding between the probe DNA and the target DNA was converted into an electrical signal using the picoammeter method to quantitatively analyze the concentration of the target DNA. With the specificity experiment, it was confirmed that the biosensor was able to discriminate between nucleotides with mismatched, non-complementary, or complementary sequences.

TiO2-DNA Nanosensor In Situ for Quick Detection of Nasal Flora in Allergic Rhinitis Patients

“…By this sensor, we successfully detect some high level of flora in AR patients including Staphylococcus aureus, Klebsiella pneumoniae, and viridans streptococci. Yoo et al [ 20 ] applied a nano-TiO 2 biosensor to the detection of E. coli, which effectively improved the targeting and specificity of the E. coli detection, consistent with the results of the present study. To our knowledge, the above floras detected in AR patients have much correlation with body infection including acute sinusitis and acute or subacute pneumonia, so we guess this may be an explanation why some AR patents tend to suffer from these two kinds of infectious disease [ 21 , 22 ].…”

Surface modification of TiO2nanoparticles with organic molecules and their biological applications

“…Yoo et al synthesized highly pure TiO 2 NPs through thermal plasma and deposited them directly on an interdigitated electrode. 56 The nanosurface of the TiO 2 -deposited electrode was modified with APTES, followed by attaching a single-stranded probe deoxyribonucleic acid (DNA) to construct a DNA biosensor for the selective detection of E. coli O157:H7, as a well-known pernicious pathogenic bacterial species. Zhang et al developed a novel electrode material for supercapacitors, in which they used APTES to link polyaniline (PANI) to TiO 2 nanowires (TNWs).…”

A Review on the Progress of Optoelectronic Devices Based on TiO2 Thin Films and Nanomaterials

“…Among the different nanoparticles, metal oxides can promote redox reactions with the measured substances and change their electrical conductivity, thus becoming a hot research topic in recent years. In addition, because of the interaction between the device and the target molecule, electron transfer can be increased, improving the sensor’s performance [ 27 ]. TiO 2 is widely used in sensing applications because of its excellent chemical properties, large specific surface area, catalytic efficiency, electrical conductivity, high physical strength, and other properties.…”