Recent Advances in Mercury Detection; Towards Enabling a Sensitive and Rapid Point-of-Check Measurement

Heavy metals emission, in particular, mercury is ever increasing due to global urbanization and industrialization. Due to increasing number of health problems related to heavy metals contamination, monitoring it becomes a crucial task for authorities and environmentalists. Therefore, the development of a nanobiosensing technique that can detect mercury ions as low as 1 ppb for its limit of quantification is necessary to provide sufficient information to ensure a sustainable and healthy environment for the community around the world. Herein we reviewed reported studies on the mercury ions bioavailability and recent progress of its detection methods. Comparison of detection methods based on electrochemical and optical technique has been made. There are two main technological gaps that need to be filled, which are sensitivity and practicality of measurement at point-of-check for in-situ analysis. the gold extraction technique, for example, is rampant across Africa and South America. This sector alone is estimated to produce 1000 tonnes of Mercury per annum [17]. If these industries are not tightly regulated, the level of heavy metals will be elevated tremendously in the environment and can cause severe problems to the biosphere [17,18]. Accumulation of heavy metal contaminants can be found in water, sludge, air, and soil. Indirect ingesting of these metals will cause bioaccumulation in living organisms and eventually will lead to biomagnification, a phenomenon of metal ions intensification in higher trophic levels [19,20]. A small amount of heavy metals including Arsenic, Chromium, and Cadmium have preferential metabolic functions. Obviously, however, it can be detrimental if it exceeds the maximum permissible limit (MPL) that is also known as the toxic dosage [21-25]. Lead, for example, is often associated with damage to the human kidney [26,27] and central nervous system [28,29]. It can also cause anemia [30], hypertension [31,32], immunotoxicity, and oxidative stress [33]. Very recently, it is suggested that the presence of lead causes a sympathovagal imbalance that leads to a high blood pressure [34]. Copper is another well-known heavy metal that is essential for human metabolism activities. Its hemeostasis is maintained by CsoR protein [35], and in the form of ceruloplasmin it aids the transport of iron to the cells [36,37]. Overexposure to this element, however, will lead to dermal toxicity [38], respiratory problem [39] and can lead to kidney damage through the up-regulation of tumor gene suppressor p53 and apoptotic gene caspase-3 [40]. Mercury, one of the top ten elements or chemicals that pose concerns in public Review ARticle