An electrochemical immunosensor employs antibodies as capture and detection means to produce electrical charges for the quantitative analysis of target molecules. This sensor type can be utilized as a miniaturized device for the detection of point-of-care testing (POCT). Achieving high-performance analysis regarding sensitivity has been one of the key issues with developing this type of biosensor system. Many modern nanotechnology efforts allowed for the development of innovative electrochemical biosensors with high sensitivity by employing various nanomaterials that facilitate the electron transfer and carrying capacity of signal tracers in combination with surface modification and bioconjugation techniques. In this review, we introduce novel nanomaterials (e.g., carbon nanotube, graphene, indium tin oxide, nanowire and metallic nanoparticles) in order to construct a high-performance electrode. Also, we describe how to increase the number of signal tracers by employing nanomaterials as carriers and making the polymeric enzyme complex associated with redox cycling for signal amplification. The pros and cons of each method are considered throughout this review. We expect that these reviewed strategies for signal enhancement will be applied to the next versions of lateral-flow paper chromatography and microfluidic immunosensor, which are considered the most practical POCT biosensor platforms.

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Thin films of gallium oxide (Ga 2 O 3 ) are prepared by using a new gallium precursor, dimethylgallium isopropoxide (DMGIP), employing both atomic layer deposition (ALD) and metal-organic (MO)CVD. The gallium precursor DMGIP, a gallium analogue of dimethylaluminum isopropoxide (DMAIP) that has been successfully used for MOCVD and ALD of aluminum oxide, is likewise a non-pyrophoric liquid at room temperature with a reasonably high vapor pressure. Using water as the oxygen source, DMGIP shows an ALD temperature window in the range 280-300 8C with a growth rate of $0.3 Å per cycle. On the other hand, using oxygen as the reactant gas in the MOCVD of Ga 2 O 3 , films are grown in the temperature range 450-6258C with the apparent activation energy of 225.5 kJ mol À1. This study shows that DMGIP can be utilized as a new source for the preparation of Ga 2 O 3 thin films.

An ellipsometric data acquisition method is introduced to measure the optical properties of sample. It is based on a microellipsometer hardware layout integrated a high numerical aperture objective lens, which is aligned in the normal direction of sample surface. This technique enables to achieve ellipsometric data at multiple incident angle with a sub-mum probe beam size, moreover real-time measurement is possible due to no moving parts. The experimental results of different SiO(2) thin film are demonstrated, also calibration technique is described.

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