鈥淔itting鈥?Makes 鈥淪ensing鈥?Simple: Label-Free Detection Strategies Based on Nucleic Acid Aptamers
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- 作者：Yan Du ; Bingling Li ; Erkang Wang
- 刊名：Accounts of Chemical Research
- 出版年：2013
- 出版时间：February 19, 2013
- 年：2013
- 卷：46
- 期：2
- 页码：203-213
- 全文大小：656K
- 年卷期：v.46,no.2(February 19, 2013)
- ISSN：1520-4898
文摘
Nucleic acid aptamers are small sequences of DNA made via in vitro selection techniques to bind targets with high affinity and specificity. The term aptamer derives from the Latin, aptus, meaning 鈥渢o fit鈥? emphasizing the lock-and-key relationship between aptamers and their binding targets. In 2004, aptamers began to attract researchers鈥?attention as new binding elements for biosensors (i.e. aptasensors). Their advantages over other sensors include a diverse range of possible target molecules, high target affinity, simple synthesis, and ability to form Watson鈥揅rick base pairs. These attributes create an enormous array of possible sensing applications and target molecules, spanning nearly all detection methods and readout techniques. In particular, aptamers provide an opportunity for designing 鈥渓abel-free鈥?sensors, meaning sensors that do not require covalently labeling a signal probe to either the analyte or the recognition element (here, the aptamer). 鈥淟abel-free鈥?systems previously could only analyze large molecules using a few readout techniques, such as when employing the other recognition elements like antibodies. 鈥淟abel-free鈥?methods are one of the most effective and promising strategies for faster, simpler, and more convenient detection, since they avoid the expensive and tedious labeling process and challenging labeling reactions, while retaining the highest degree of activity and affinity for the recognition element. 鈥淟abel-free鈥?sensors are one of the most promising future biosensors.
In this Account, we describe our efforts exploring and constructing such label-free sensing strategies based on aptamers. Our methods have included using various readout techniques, employing novel nanomaterials, importing lab-on-a-chip platforms, and improving logical recognition. The resulting sensors demonstrate that aptamers are ideal tools for 鈥渓abel-free鈥?sensors. We divide this Account into three main parts describing three strategies for designing 鈥渓abel-free鈥?sensors: (1) Label-free, separation-free strategies. These include colorimetric sensors based on G-quadruplex-hemin complex, and fluorescent sensors based on fluorescent small molecules, novel conjugated polymers, and metal ion clusters. (2) Label-free, separation-required strategies. In this part, electrochemical sensors are introduced, including sensors with different subtechniques using an electrode array. (3) Logic sensors. Some logic recognition systems are introduced.
We emphasize that label-free aptasensors are not merely simple. We hope our introduction illustrates the powerful, flexible, and smart functions of aptamers in carrying out various detection tasks or playing various recognition games. Our work is only a start. We believe this field will bring additional knowledge on general designs, anti-interference, multianalysis, minimization, and auto-operation of aptamer biosensors.
In this Account, we describe our efforts exploring and constructing such label-free sensing strategies based on aptamers. Our methods have included using various readout techniques, employing novel nanomaterials, importing lab-on-a-chip platforms, and improving logical recognition. The resulting sensors demonstrate that aptamers are ideal tools for 鈥渓abel-free鈥?sensors. We divide this Account into three main parts describing three strategies for designing 鈥渓abel-free鈥?sensors: (1) Label-free, separation-free strategies. These include colorimetric sensors based on G-quadruplex-hemin complex, and fluorescent sensors based on fluorescent small molecules, novel conjugated polymers, and metal ion clusters. (2) Label-free, separation-required strategies. In this part, electrochemical sensors are introduced, including sensors with different subtechniques using an electrode array. (3) Logic sensors. Some logic recognition systems are introduced.
We emphasize that label-free aptasensors are not merely simple. We hope our introduction illustrates the powerful, flexible, and smart functions of aptamers in carrying out various detection tasks or playing various recognition games. Our work is only a start. We believe this field will bring additional knowledge on general designs, anti-interference, multianalysis, minimization, and auto-operation of aptamer biosensors.