Table 1.

A comparison of different types of mercury sensors.

Type of sensor	Sensing principle	Fabrication of the sensor	Forms of mercury detected	Detection limit	Ref.
Biosensor	Mercury interaction with bacterial cell	Moderately difficult	Inorganic Hg Organic Hg	∼10−7M	[24]
	Mercury interaction with antibody	Moderately difficult	Hg2+	∼10−6 M	[29]
Chemical sensor	Fluorescence quenching	Moderately difficult	Hg2+	∼10−6M	[30]
	Fluorescence enhancing	Moderately difficult	Hg2+	∼10−9M	[31–33]
Conductometric sensor	Conductivity/resistance	Easy	Hg vapor	∼10−8 M	[38–40]
Microcantilever sensor	Physical property changes	Easy	Hg2+, Hg0	∼10−11 M	[41–43]
SAW sensor	Oscillation frequency	Easy	Hg vapor	∼10−8 M	[44]
Piezoelectric sensor	Frequency of vibration	Easy	Hg0	∼10−9M	[47–48]
Nanosensor	Interaction with nanoparticles	Moderately difficult	Hg2+	10−11∼10−15 M	[9–10]