Hg
2+
has a significant hazardous impact on the environment
and ecosystem. There is a great demand for new methods with high selectivity
and sensitivity to determine mercury in life systems and environments.
In this paper, a novel turn-on Hg
2+
fluorescent probe has
been reported with a naphthalimide group. The Hg
2+
fluorescent
probe was designed by the inspiration of the well-known specific Hg
2+
-triggered thioacetal deprotection reaction. A 1,2-dithioalkyl
group was chosen as the specific recognition site of Hg
2+
. The probe showed weak fluorescence without Hg
2+
, and
the color of the solution was light yellow. In the presence of Hg
2+
, the probe reacted specifically with the mercury ion to
produce an aldehyde and emitted strong fluorescence, and the color
of the solution also turned light green, thus realizing the monitoring
of the mercury ion. The Hg
2+
fluorescent probe showed outstanding
sensitivity and selectivity toward Hg
2+
. Furthermore, the
Hg
2+
fluorescent probe could work in a wide pH range. The
linear relationship between the fluorescence intensity at 510 nm and
the concentration of Hg
2+
was obtained in a range of Hg
2+
concentration from 2.5 × 10
–7
to
1.0 × 10
–5
M. The detection limit was found
to be 4.0 × 10
–8
M for Hg
2+
. Furthermore,
with little cell toxicity, the probe was successfully applied to the
confocal image of Hg
2+
in PC-12 cells.