Comparison of a potentiometric and a micromechanical triglyceride biosensor

Dynamic response of polysilicon microcantilevers to enzymatic hydrolysis of urea

“…This was followed by treating the samples in 3% APTES in toluene for 3 h at 120°C for silanization. The silanized samples were treated in a 10% solution of glutaraldehyde in DI water for 2 h at room temperature [6,7] and then immersed in urease solution (0.1 mg/ml DI water) for 24 h before being rinsed in DI water in order to remove the adsorbed enzymes.…”

Porous Silicon-based Electrochemical Biosensors

“…Potentiometric -Immobilised lipase in PSi -<15mM (Setzu et al 2007) Potentiometric, PSi electrode, lipase in solution 30mV/pH unit 5-40mM (Reddy et al 2003) Impedimetric -Polyanilyne nanotubes 2.59 × 10 −3 KΩ −1 mg −1 dL 25-300 mg dL −1 (Dhand et al 2009) pH measurements -lipase on silica beads -tributyrin 0.478 pH/mM <4 mM (Pijanowsk et al 2001) pH measurements -lipase on silica beads -triacetin 0.022 pH/mM <30 mM (Pijanowsk et al 2001) Potentiometric -EISCAP 500 µM 8mM (Fernandez et al 2009) Micromechanical 10 µM 500µM (Fernandez et al 2009) ENFET -lipase on magnetic nanoparticles -5-30mM (Vijayalakshmi et al 2008) Dhand and coworkers (Dhand et al 2009) using a polianilyne nanotube film obtained a linear response range of 25-300 mg dL −1 , a sensitivity of 2.59 × 10 −3 KΩ −1 mg −1 dL, with a response time of 20 s and regression coefficient of 0.99. Pijanowsk and coworkers studied a pH detector based on silica gel beads immobilised with a lipase in a microreactor (Pijanowsk et al 2001).…”

“…The higher sensitivity was obtained for tributyrin with 0.478 pH/mM for concentration < 4 mM, while the widest linear range, up to 30 mM, was obtained using triacetin but with a significantly lower sensitivity (0.022pH/mM). Fernandez and coworkers compared two kind of Si-based biosensors (Fernandez et al 2009). The first one was an EISCAP (electrolyte-insulator-semiconductor capacitor) sensor built depositing silicon nitride on p-type Si substrate and used for potentiometric transduction, while the second was a Si-based micromechanical sensor whose detection method is based on the measurement of the resonance frequency of a cantilever immersed in a solution containing the enzyme substrate.…”

Shape effects of micromechanical cantilever sensor

“…In this paper, Young's Modulus for a silicon dioxide (SiO 2 ) cantilever is 57-79 GPa [14,15], and I is the moment of inertia, or wt 3 / 12, for the rectangular cross-section of the cantilever. The cantilever dimensions include the length (l), the width (w) and the thickness (t).…”