3 Aptamer-Based Point of Care Testing Schemes
71
Wang et al. reported a multiparameter paper-based electrochemical aptasensor
for simultaneous detection of carcinoembryonic antigen (CEA) and neuron-specific
enolase (NSE) in a clinical sample with high sensitivity and specificity. The paperbased device was developed through wax printing and screen-printing, which enabled
functions of sample filtration and sample auto-injection. Amino functional graphene
(NG)-Thionin (THI)-AuNPs and Prussian blue (PB)-poly (3,4- ethylenedioxythiophene) (PEDOT)-AuNPsnano-composites were synthesized respectively. The LOD
was 2 pg.mL
−1 for CEA and 10 pg.mL
−1 for NSE [92].
Hu et al. reported a universal aptamer system based on the advantage of
dsDNA/perilinediimide (PDI) as the signal probe for multiplexed detection of small
molecules, adenosine and cocaine. A structure-switching enzymatic recycling was
used for signal amplification. High quenching efficiency combined with autocatalytic
target recycling amplification delivered the LOD of 400 nM for adenosine. Simultaneous and multicolor analysis of several small molecules in homogeneous solution was also achieved by the proposed sensing system, demonstrating its potential
application in the rapid screening of multiple bio-targets [93].
3.4 Conclusion and Future Trends
Even though aptamers have shown obvious advantages of high affinity and specificity, batch-to-batch reproducibility for ultrasensitive and accurate POCT, the long
historical and powerful nature of antibody utilization may continue to suppress
aptamer usage in the commercial diagnostics market. Successful aptamers with
enough affinity, selectivity and good performance in reality are continued to be
expected. Another way for aptamers to get rid of the prejudice against them is their
killer applicative use in highly desirable detection formats of biosensors in which
antibodies either do not work at all or work poorly. In addition, to address the costs
associated with fluorometers, the colorimetric detection of small molecular targets is a
possible avenue for selective use of aptamers where antibodies fail or have many difficulties/inconveniences. As it is extremely challenging to develop antibodies against
small molecular targets, consistent successful demonstration of aptamers as molecular recognition elements for the detection of small molecules is likely to bring
aptamers closer to commercial technology development. Recent developments such
as integrating the nanomaterials with aptamers are likely to break the current ideals
and encourage broader use of aptamers in diagnostic platforms of the next decade.
71
Wang et al. reported a multiparameter paper-based electrochemical aptasensor
for simultaneous detection of carcinoembryonic antigen (CEA) and neuron-specific
enolase (NSE) in a clinical sample with high sensitivity and specificity. The paperbased device was developed through wax printing and screen-printing, which enabled
functions of sample filtration and sample auto-injection. Amino functional graphene
(NG)-Thionin (THI)-AuNPs and Prussian blue (PB)-poly (3,4- ethylenedioxythiophene) (PEDOT)-AuNPsnano-composites were synthesized respectively. The LOD
was 2 pg.mL
−1 for CEA and 10 pg.mL
−1 for NSE [92].
Hu et al. reported a universal aptamer system based on the advantage of
dsDNA/perilinediimide (PDI) as the signal probe for multiplexed detection of small
molecules, adenosine and cocaine. A structure-switching enzymatic recycling was
used for signal amplification. High quenching efficiency combined with autocatalytic
target recycling amplification delivered the LOD of 400 nM for adenosine. Simultaneous and multicolor analysis of several small molecules in homogeneous solution was also achieved by the proposed sensing system, demonstrating its potential
application in the rapid screening of multiple bio-targets [93].
3.4 Conclusion and Future Trends
Even though aptamers have shown obvious advantages of high affinity and specificity, batch-to-batch reproducibility for ultrasensitive and accurate POCT, the long
historical and powerful nature of antibody utilization may continue to suppress
aptamer usage in the commercial diagnostics market. Successful aptamers with
enough affinity, selectivity and good performance in reality are continued to be
expected. Another way for aptamers to get rid of the prejudice against them is their
killer applicative use in highly desirable detection formats of biosensors in which
antibodies either do not work at all or work poorly. In addition, to address the costs
associated with fluorometers, the colorimetric detection of small molecular targets is a
possible avenue for selective use of aptamers where antibodies fail or have many difficulties/inconveniences. As it is extremely challenging to develop antibodies against
small molecular targets, consistent successful demonstration of aptamers as molecular recognition elements for the detection of small molecules is likely to bring
aptamers closer to commercial technology development. Recent developments such
as integrating the nanomaterials with aptamers are likely to break the current ideals
and encourage broader use of aptamers in diagnostic platforms of the next decade.