70
G. Murtaza et al.
Upon addition of KAN and STR, the aptamers bound to their targets and led to the
complementary strands released from the aptamers and more changes of current
peaks. Under the optimized conditions, this aptasensor showed a high stability
and selectivity toward KAN and STR with LOD as low as 87.3 and 45.0 pM,
respectively [89].
Similarly, Wu et al. presented a colorimetric aptasensor for multiple antibiotics
based on an ss-DNA fragment. The multifunctional aptamer was designed to be
adsorbed on AuNPs surfaces acting as a binding element for antibiotics and a molecular switch. Chloramphenicol (CAP) and tetracycline (TET) were selected as the
model antibiotics. When one kind of antibiotics was added, the specifically recognized fragment of Apt bound to it and dissociated, and the nonspecific one controls
AuNPs aggregation under high-salt conditions. The changes of AuNPs solution color
were used as the signal readout (Fig. 3.9). The aptasensor exhibited remarkable selectivity and sensitivity for separate detection of TET and CAP, and the LODs of 32.9
and 7.0 nM, respectively [90].
Wei et al. reported a portable multiplexed bar chart SpinChip (MB-SpinChip) integrated with nanoparticle-mediated magnetic aptasensors developed for instrumentfree detection of multiple pathogens including Salmonella enterica, Escherichia
coli, and Listeria monocytogenes. This multiplexed SpinChip combined aptamerspecific recognition and nanoparticle-catalyzed pressure amplification to achieve a
sample-to-answer output for sensitive POCT [91].
Fig. 3.9 Schematic illustration of the detection TET/CAP based on AuNPs colorimetric aptasensors. The Apt acts as a molecular switch adjusting the AuNPs aggregation. When antibiotics remove
the fragment of Apt from the AuNPs surface, unbalanced AuNPs was aggregated of different scales
under high-salt conditions. It thereby causes colloidal color changes, which can be detected by
UV-spectrum and smartphone analysis, respectively (Reproduced from [90] with permission from
Elsevier)
G. Murtaza et al.
Upon addition of KAN and STR, the aptamers bound to their targets and led to the
complementary strands released from the aptamers and more changes of current
peaks. Under the optimized conditions, this aptasensor showed a high stability
and selectivity toward KAN and STR with LOD as low as 87.3 and 45.0 pM,
respectively [89].
Similarly, Wu et al. presented a colorimetric aptasensor for multiple antibiotics
based on an ss-DNA fragment. The multifunctional aptamer was designed to be
adsorbed on AuNPs surfaces acting as a binding element for antibiotics and a molecular switch. Chloramphenicol (CAP) and tetracycline (TET) were selected as the
model antibiotics. When one kind of antibiotics was added, the specifically recognized fragment of Apt bound to it and dissociated, and the nonspecific one controls
AuNPs aggregation under high-salt conditions. The changes of AuNPs solution color
were used as the signal readout (Fig. 3.9). The aptasensor exhibited remarkable selectivity and sensitivity for separate detection of TET and CAP, and the LODs of 32.9
and 7.0 nM, respectively [90].
Wei et al. reported a portable multiplexed bar chart SpinChip (MB-SpinChip) integrated with nanoparticle-mediated magnetic aptasensors developed for instrumentfree detection of multiple pathogens including Salmonella enterica, Escherichia
coli, and Listeria monocytogenes. This multiplexed SpinChip combined aptamerspecific recognition and nanoparticle-catalyzed pressure amplification to achieve a
sample-to-answer output for sensitive POCT [91].
Fig. 3.9 Schematic illustration of the detection TET/CAP based on AuNPs colorimetric aptasensors. The Apt acts as a molecular switch adjusting the AuNPs aggregation. When antibiotics remove
the fragment of Apt from the AuNPs surface, unbalanced AuNPs was aggregated of different scales
under high-salt conditions. It thereby causes colloidal color changes, which can be detected by
UV-spectrum and smartphone analysis, respectively (Reproduced from [90] with permission from
Elsevier)