72 CHEMICAL SENSORS: FUNDAMENTALS. VOLUME 2: NANOSTRUCTURED MATERIALS an Au electrode to form a glucose electrode. The fabricated electrode can then be loaded into a poten- tiostat and serve as the working electrode. Glucose will bond with enzyme (glucose oxidase), and the bonding strength can be determined in cyclic voltammetry measurements at a certain voltage. As a result, the intensity variation in cyclic voltammograms is related to the concentration of glucose. This biosensing technique is widely used in biochemical and electrochemical experiments. Q1D nanowire with large surface area can effectively capture more biological molecules and deliver stronger signal; however, using Q1D metal oxides usually results in degradation of electrode performance in solution. Most metal oxides are quite chemically active and have weak chemical resistance. Q1D metal oxides of high reactive surface, such as ZnO, In 2 O 3 , SnO 2 , etc., are usually vulnerable in acid/alkaline solutions. This might cause stability issues and false detection due to a corroded surface structure. To overcome this critical problem, additional protective coating needs to be applied to protect the Q1D surface, however, this may result in a decrease of sensitivity (Zang et al. 2007; Umar et al. 2009). 5. SUMMARY AND FUTURE OUTLOOK In this chapter we have presented recent progress in the studies of Q1D metal oxide nanomaterials. The topics include nanomaterial growth, structure and property characterizations, and the exploration of their chemical gas sensor applications. In the past few years, synthesis of metal oxide Q1D structures has