Sensing Heavy Metals Using Mesoporous-Based Optical Chemical Sensors

Table 3

Sensors for Hg²⁺ determination.

Indicator dye	Material	Detection principle	Working range (M)	LOD (M)	𝑡𝑅 (s)	Ref.
Squarine	UVM-7	Absorption (turn-on)	4.9×10^−7--4.9×10^−4	4.9×10^−7	120	[19]
TPPS	HOM-9	Absorption (colour change)	5.9×10^−9--1.7×10^−5	5.9×10^−9	60	[20]
Acyclic dye	SBA-15	Absorption (colour change)	1--10×10^−6	1×10^−6	~10	[21]
R6G	SBA-15	Fluorescence enhancement	4.9×10^−9--4.5×10^−7	4.9×10^−9	Not given	[22]
R6G	SBA-15	Fluorescence enhancement	4.9×10^−9--6.5×10^−8	4.9×10^−9	Not given	[23]
R6G	SBA-15	Fluorescence enhancement	1×10^−8--4×10^−8	1×10^−8	Not given	[24]
Pyrene	SBA-15	Fluorescence enhancement	8.5×10^−7--2×10^−5	8.5×10^−7	Few seconds	[25]
Ethynylpyrene	SBA-15	Fluorescence enhancement	0.2×10^−8--3×10^−5	2×10^−8	Not given	[26]
DS	SBA-15	Fluorescence quenching	10^−6–10^−3	10^−6	Not given	[27]
RhB	SBA-15	Fluorescence (turn-on)	Not given	1.5×10^−8	Not given	[28]
RhB	Au-HMS	Fluorescence (turn-on)	7×10^−8--7.5×10^−6	7×10^−8	100	[29]
Pyrene	Core-shell MPS NPs	Fluorescence enhancement	1.7×10^−8--9×10^−5	1.7×10^−8	Not given	[30]
Pyrene	Core-shell MPS NPs	Fluorescence enhancement	8.5×10^−7--9×10^−5	8.5×10^−7	14	[31]
Azo dye	MCM-41 NPs	Absorption (colour change)	Not given	9.97×10^−6	Not given	[32]
Eu(PTA)	MCM-41	Fluorescence quenching	1--12×10^−6	1×10^−6	Not given	[33]