Nanomaterial gas sensors for biosensing applications: A Review
Background: Nanomaterial is one of the most used materials for various gas sensing application to detect toxic gases, human breath, and other specific gas sensing. One of the most important applications of nanomaterial based gas sensors is as biosensing applications. In this review article, the gas sensors for biosensing are discussed by classifying gas sensors on the basis of crystalline structure and different categories of nanomaterial. Methods: In this paper, firstly rigorous efforts has been made to find out research questions by going through structured and systematic survey of available peer reviewed high quality articles in this field. The papers related to nanomaterial based biosensors are then reviewed qualitatively to provide substantive findings from the recent developments in this field. Results: In this review article, firstly classifications of nanomaterial gas sensors have been presented on the basis of crystalline structure of nanomaterial and different types of nanomaterial available for biosensing applications. Further, the gas sensors based on nanomaterial for biosensing applications are collected and reviewed in terms of their performance parameters such as sensing material used, target gas component, detection ranges (ppm-ppb), response time, operating temperature and method of detection etc. The different nanomaterials possess slightly different sensing and morphological properties due to their structure, therefore, it can be said that a nanomaterial must be selected carefully for particular application. The 1D nanomaterials show best selectivity and sensitivity for gases available in low concentration ranges due to their miniaturised structure as compared to 2D and 3D nanomaterials. However, these 2D and 3D nanomaterials also so good sensing properties compared to bulk semiconductor materials. The polymer and nanocomposites have opened door for future research and have great potential for new generation gas sensor for detecting biomolecules. Conclusion: These nanomaterials extend great properties towards sensing application of different gases for lower concentration of particular gas particles. Nano polymer and nano composites have great potential to be used gas sensor for detection of biomolecules.