Low temperature co-fired ceramic (LTCC)based biosensor for detection of vanadium using immobilized Arachis hypogaea alkaline phosphatase on multi walled carbon nanotubes ethyl cellulose sponge matrix

916-920Studies on enzyme based thermometric biosensor are limited. Here, we report on fabrication of an alkaline phosphate based thermometric biosensor. We designed alkaline phosphatase inhibition based biosensor for detection of vanadium using immobilized alkaline phosphatase on multi walled carbon nano tubes (MWCTs) ethyl cellulose sponge matrix. We isolated protein from plant source, partially purified and fabricated a miniature ceramic viz. LTCC (low temperature co-fired ceramics technology) based biosensor for detection of vanadium. This biosensor consists of a microreaction chamber with buried heaters. Alkaline phosphatase has been isolated from the seeds of ‘Arachis hypoghaea’ was studied for its biochemical properties viz. optimum pH and temperature. The partially purified enzyme was immobilized using carboxyl-functionalised carbon nanotubes (CNTs) by cross linking with epichlorohydrin (ECH) along with a matrix of ethyl cellulose. The developed LTCC based biosensor on testing indicated its linear response to vanadium concentration up to 9 mM with a relatively high sensitivity of about 147 nA/mM. Thus, we have demonstrated a LTCC based biosensor using immobilized alkaline phosphatase for detection of vanadium

Low temperature co-fired ceramic (LTCC)- based biosensor for detection of vanadium using immobilized Arachis hypogaea alkaline phosphatase on multi walled carbon nanotubes ethyl cellulose sponge matrix

Studies on enzyme based thermometric biosensor are limited. Here, we report on fabrication of an alkaline phosphate based thermometric biosensor. We designed alkaline phosphatase inhibition based biosensor for detection of vanadium using immobilized alkaline phosphatase on multi walled carbon nano tubes (MWCTs) ethyl cellulose sponge matrix. We isolated protein from plant source, partially purified and fabricated a miniature ceramic viz. LTCC (low temperature co-fired ceramics technology) based biosensor for detection of vanadium. This biosensor consists of a microreaction chamber with buried heaters. Alkaline phosphatase has been isolated from the seeds of ‘Arachis hypoghaea’ was studied for its biochemical properties viz. optimum pH and temperature. The partially purified enzyme was immobilized using carboxyl-functionalised carbon nanotubes (CNTs) by cross linking with epichlorohydrin (ECH) along with a matrix of ethyl cellulose. The developed LTCC based biosensor on testing indicated its linear response to vanadium concentration up to 9 mM with a relatively high sensitivity of about 147 nA/mM. Thus, we have demonstrated a LTCC based biosensor using immobilized alkaline phosphatase for detection of vanadium

Electrochemical co-deposition of ternary Sn-Bi-Cu films for solder bumping applications

This paper reports the co-deposition of Sn-Bi-Cu films using stannic salt bath which has good stability for up to a week. The effect of current density and bath stirring on the film composition and microstructure has been studied. The deposited films are rich in the more noble metal Bi at current densities up to 5 mA cm(-2) but stabilize to about 49 wt.% Bi, 47 wt. % Sn and 4 wt. % Cu at 10 mA cm(-2) and beyond, indicating the effect of limiting current density. There is improvement in the microstructure with stirring or aeration, but the film composition reverts to the Bi rich state, with close to 90 wt.% Bi for deposition at 5 mA cm(-2). This is attributed to the dispersion of Sn2+ ions generated at the cathode during the two-step reduction of Sn4+ ions, due to stirring. The bath is suitable for near eutectic compositions of Sn-Bi with < 5 wt.% Cu content

Synthesis of low coercive BaFe₁₂O₁₉ hexaferrite for microwave applications in low-temperature cofired ceramic

Polycrystalline M-type barium hexaferrite (BaFe₁₂O₁₉) samples have been synthesized by solution combustion route at different pH and calcination conditions in order to reduce the coercivity for microwave applications in low-temperature cofired ceramic (LTCC) substrates. Structural, morphological, and magnetic properties of BaFe₁₂O₁₉ were studied by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, vibrating sample magnetometry (VSM), and Mössbauer spectroscopy. The formation of a single-phase hexagonal structure was confirmed by XRD. The Raman spectra reveal all characteristic peaks of BaFe₁₂O₁₉, illustrating the phase purity and crystal lattice symmetry of the synthesized material. Mössbauer spectra illustrate the existence of Fe³⁺ cations at all five crystallographic lattice sites. The microstructural features observed by FESEM disclose the growth of nanoregime particles into hexagonal platelet particles after calcination at temperatures from 800&#176;C to 1200&#176;C. The VSM results show a lower coercivity (1350 Oe to 3500 Oe) together with reasonably high saturation magnetization (55 emu/g to 60 emu/g) and a high bulk resistivity (&#62;10⁹ &#937;-cm) at room temperature. The dependence of magnetic and electrical properties on the preparation and processing conditions is also discussed