reported air stable high performance BP encapsulated by ionophore coating. This
layer is used as a gating material in which adsorption mechanism of Pb (II) ions
were studied according to Langmuir Blogett isotherm. The author had reported the
sensitivity towards Pb (II) to be 1 ppb. The paper is written so nicely that, every
aspect is covered very nicely [44] (Fig. 5).
Silicon nanowires (SiNWs) are pseudo one-dimensional (1D) assemblies with a
diameter of less than 100 nm resulting in larger surface to volume ratio. Hence,
suitable for various electronic applications. For sensing, the small volume will
excellently tolerate and respond to very small input signal making them suitable for
chemical sensing and biochemical sensing [60]. The author had reported
3-mercaptopropyltriethoxysilane (MPTES) functionalized Silicon nanowires, to
sense Hg
2+ and Cd
2+ ions. Through I-V characteristics, the CHEMFET demonstrated high selectivity and sensitivity with a detection limit down to 10
−7
M for
Hg
2+ and 10
−4
M for Cd
2+ ions [61].
Other Materials: The HEMT (or High Electron Mobility Transistor) is a new class
of high performance transistor having a combination of low noise figure and very
high levels of presentation at frequencies lying in microwave region. This is a
significant device for designing high speed digital and microwave circuits. It
comprises of PN junction known as Metal semiconductor junction (MESFET) or
Schottky barrier [62].
Fig. 5 a Photograph of OTFT sensor with 2µL Hg
2+ ion droplet on the channel, b binding
mechanism of Hg
2+ to py-SH, c colour plot for DI DS /I DS0 of Hg
2+ ion concentrations ranging from
1 mM to 1 µM, d linear fitting of 150 to 1 µM concentration of Hg
2+ [44]
118
C. Sharma et al.
layer is used as a gating material in which adsorption mechanism of Pb (II) ions
were studied according to Langmuir Blogett isotherm. The author had reported the
sensitivity towards Pb (II) to be 1 ppb. The paper is written so nicely that, every
aspect is covered very nicely [44] (Fig. 5).
Silicon nanowires (SiNWs) are pseudo one-dimensional (1D) assemblies with a
diameter of less than 100 nm resulting in larger surface to volume ratio. Hence,
suitable for various electronic applications. For sensing, the small volume will
excellently tolerate and respond to very small input signal making them suitable for
chemical sensing and biochemical sensing [60]. The author had reported
3-mercaptopropyltriethoxysilane (MPTES) functionalized Silicon nanowires, to
sense Hg
2+ and Cd
2+ ions. Through I-V characteristics, the CHEMFET demonstrated high selectivity and sensitivity with a detection limit down to 10
−7
M for
Hg
2+ and 10
−4
M for Cd
2+ ions [61].
Other Materials: The HEMT (or High Electron Mobility Transistor) is a new class
of high performance transistor having a combination of low noise figure and very
high levels of presentation at frequencies lying in microwave region. This is a
significant device for designing high speed digital and microwave circuits. It
comprises of PN junction known as Metal semiconductor junction (MESFET) or
Schottky barrier [62].
Fig. 5 a Photograph of OTFT sensor with 2µL Hg
2+ ion droplet on the channel, b binding
mechanism of Hg
2+ to py-SH, c colour plot for DI DS /I DS0 of Hg
2+ ion concentrations ranging from
1 mM to 1 µM, d linear fitting of 150 to 1 µM concentration of Hg
2+ [44]
118
C. Sharma et al.