Portable Low-Cost Miniature Sensors for Environmental Monitoring

Growing human activities around the world in the form of industries, agriculture, mining, vehicular, etc. are introducing toxic substances into our environment. Toxic pollutants in our environment are harming the human population, plants, and animals. Environmental monitoring is essential to protect humans and the environment from toxic substances. Many new types of sensors are being developed for monitoring different types of toxic substances. Among them, portable miniaturized sensors represent cost-effective sensing systems, which can be transported to remote areas with considerable ease. An ideal on-site chemical analysis system must be inexpensive, fully automated, and compatible with a broad range of samples. For instance, they can also be utilized for monitoring the presence of foreign substances in the human body. The present review covers emerging miniaturized sensor technologies for various environmental contaminants that fall into the following categories: (a) volatile organic contaminants (b) toxic metal ions (c) anions (d) biological contaminants, and (e) pesticides. The aim of the review is to present various miniature sensors from the user and constructor’s point of view. A comparative review of emerging sensor technologies with respect to their sensitivity, selectivity, and applicability can help the reader in developing new technology for future environment pollution concerns and also direct them to utilize existing technologies for a particular environmental problem.