
81Fluorescent Sensors Based on Energy Transfer and Charge Transfer
negligible SPR, which quenches the uorescence of the QD via the NSET mechanism. The
NSET sensors exhibit an LOD of 0.4 and 1.2 ppb toward Hg(II) ions in the buffer solution
and in river water, respectively [60]. Ray group has also demonstrated that the NSET sen-
sor is able to detect Hg
2+
in drinking water, river water, and solid samples [61]. In addition,
a uorescent sensor has used the NSET mechanism to detect Hepatitis C virus RNA [62].
The Au NPs have distinct advantages as the acceptors in the energy transfer–based sen-
sors [31]: (1) high uorescence-quenching efciency