Highly Sensitive Biofunctionalized Mesoporous Electrospun TiO₂ Nanofiber Based Interface for Biosensing

Abstract

ABSTRACT:The surface modified and aligned mesoporous anatase titania nanofiber mats (TiO 2 −NF) have been fabricated by electrospinning for esterified cholesterol detection by electrochemical technique. The electrospinning and porosity of mesoporous TiO 2 −NF were controlled by use of polyvinylpyrrolidone (PVP) as a sacrificial carrier polymer in the titanium isopropoxide precursor. The mesoporous TiO 2 − NF of diameters ranging from 30 to 60 nm were obtained by calcination at 470°C and partially aligned on a rotating drum collector. The functional groups such as −COOH, −CHO etc. were introduced on TiO 2 −NF surface via oxygen plasma treatment making the surface hydrophilic. Cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) were covalently immobilized on the plasma treated surface of NF (cTiO 2 −NF) via N-ethyl-N0-(3-dimethylaminopropyl carbodiimide) and N-hydroxysuccinimide (EDC-NHS) chemistry. The high mesoporosity (∼61%) of the fibrous film allowed enhanced loading of the enzyme molecules in the TiO 2 −NF mat. The ChEt-ChOx/cTiO 2 −NF-based bioelectrode was used to detect esterified cholesterol using electrochemical technique. The high aspect ratio, surface area of aligned TiO 2 −NF showed excellent voltammetric and catalytic response resulting in improved detection limit (0.49 mM). The results of response studies of this biosensor show excellent sensitivity (181.6 μA/mg dL −1 /cm 2 ) and rapid detection (20 s). This proposed strategy of biomolecule detection is thus a promising platform for the development of miniaturized device for biosensing applications.

Recent Advances in the Synthesis of Metal Oxide Nanofibers and Their Environmental Remediation Applications

“…There are many methods such as melt, colloid, solution, dry and co-axial electrospinning, CVD, PECVD, and electrochemical methods that are used to yield metal oxide and nanofibers [14,15,[104][105][106][107][108]. In recent times, electrospun metal oxides' precursors have garnered much interest for the production of multifunctional nanofibers [109,110].…”

“…In the case of electrospinning from an inorganic precursor, the high-temperature calcination process causes a reduction in the diameter of the fibers as the sacrificial polymer template is selectively removed. Consequently, by reason of calcination, the resultant nanofibers become fragile owing to their thinner cross sections and the thermomechanical stress generated from the reduction in size [105,[120][121][122]. There have been many efforts made in recent times towards the production of metal oxide nanofibers by the electrospinning route.…”

“…Recently, Ali et al [187] fabricated a microfluidic immuno-biochip to detect breast cancer biomarkers that is based on a hierarchical composite of porous graphene and electrospun TiO 2 nanofibers. Direct electrospinning of titania nanofibers on a conducting electrode was used to construct a cholesterol biosensor ( Figure 14 describes the synthesis and application of nanofibers as an enzymatic biosensor) that can detect esterified cholesterol from human blood with excellent sensitivity (181.6 µA/mg·dL −1 /cm 2 ) and rapid detection (20 s) [105]. Additionally, metal oxide nanofibers have found huge importance in immunolabeling, cell and molecular bioimaging, biosensing, treatment of tumor cells, soil nutrient sensing, and numerous photosensitive applications [188][189][190][191][192].…”

Anti-epidermal growth factor receptor conjugated mesoporous zinc oxide nanofibers for breast cancer diagnostics

“…11 One dimensional (1D) nanorods, nanowires and nanofibers of zinc oxide (ZnO) have been predicted to have considerable potential for biomedical applications including DNA delivery, bioimaging, magnetic resonance imaging, nanoelectronics and biosensors devices due to their higher surface-to-volume ratio, excellent electron transfer communication, environmental safety, biocompatibility, nontoxicity, chemical stability and biodegradability. [12][13][14][15][16] The anisotropic structure of ZnO is known to exhibit higher electron mobility and diffusion co-efficient compared to other metal oxides like titanium oxide. 17 Nanofibers of ZnO due to their high surface-to-volume and aspect ratios can play an important role in electrochemical biosensors.…”

A gelatin based antioxidant enriched biomaterial by grafting and saturation: Towards sustained drug delivery from antioxidant matrix

“…The conjugation of sulfur containing GSH and amide cross linkage into gelatin network was achieved using simple EDC/NHS method [21,22]. According to the procedure reported earlier, gelatin solution (3% w/v) was prepared by dissolving in 10 mL of MES buffer (10×) at pH 6 to activate carboxyl groups.…”