What Are Aptamer-Based Biosensors & Their Applications?

Aptamer-based biosensors typically consist of three components: the aptamer as the recognition element, a transducer, and a signal output. The aptamer binds to the target molecule, and this binding event is then transduced into a detectable signal by the transducer. The signal output can be either optical, electrochemical, or mass-based, depending on the transducer used.

Aptamer-based biosensors have several advantages over traditional diagnostic tools. Firstly, aptamers are highly specific and selective, enabling the detection of low concentrations of the target molecule in complex samples. Secondly, aptamers are stable and can be easily synthesized, modified, and labelled with various signaling molecules, making them highly adaptable to different diagnostic platforms. Thirdly, aptamers have low immunogenicity, making them suitable for use in humans and animals.

Aptamer-based biosensors have been used in a wide range of diagnostic applications, including the detection of small molecules, proteins, and even cells. Here are some examples of their applications:

Detection of Small Molecules:

Aptamers can be used to detect small molecules such as adenosine, cocaine, and glucose. For example, an aptamer-based biosensor for adenosine detection was developed by immobilizing an adenosine aptamer onto a gold electrode. The aptamer binds to adenosine, causing a change in the electrode potential, which can be detected by an electrochemical transducer¹.

Detection of Proteins:

Aptamers can be used to detect proteins such as cytokines, antibodies, and enzymes. For example, an aptamer-based biosensor for the detection of α-fetoprotein (AFP), a biomarker for liver cancer, using a silicon-based photonic crystal microcavity combined with an aptamer amplification strategy. The aptamer was used to capture and amplify the signal of AFP, resulting in ultrasensitive detection with a limit of detection of 0.15 pg/mL. The biosensor showed excellent specificity and selectivity for AFP and could detect AFP in serum samples with good accuracy. This study demonstrates the potential of aptamer-based biosensors for the detection of protein biomarkers in clinical samples².

Detection of Cells:

Aptamers can also be used to detect cells such as cancer cells and bacteria. For example, an aptamer-based biosensor for the detection of E. coli using fluorescence polarization. The biosensor showed high sensitivity and selectivity for E. coli, with a limit of detection of 1.1 × 10^3 CFU/mL. The biosensor was also able to detect E. coli in spiked milk samples with good accuracy. This study demonstrates the potential of aptamer-based biosensors for the detection of bacterial pathogens in food and environmental samples³.

The translation of aptamer-based biosensors from the laboratory to the clinic has been slow. One of the main reasons for this is the lack of standardized protocols for aptamer selection, characterization, and validation, which has resulted in a wide range of aptamer-based biosensors with varying performance characteristics. In addition, the regulatory hurdles and the conservative nature of the diagnostics industry have slowed the adoption of aptamer-based biosensors in clinical settings. Nevertheless, ongoing research efforts are aimed at addressing these challenges and improving the performance and utility of aptamer-based biosensors for diagnostic applications. With further research and development, aptamer-based biosensors have the potential to revolutionize the field of diagnostics and improve patient outcomes through earlier and more accurate detection of diseases.

At NeoVentures Biotechnology, we are spearheading a groundbreaking revolution in the creation of aptamer-based biosensors. Our next-generation aptamer selection approach ensures enhanced stability, selectivity, and sensitivity, making these biosensors highly robust and reliable for commercial applications. Through this innovative platform, we are poised to transform the landscape of biosensing technology, opening new possibilities for rapid, accurate, and cost-effective diagnostic solutions. Contact our team for further information here.

 

¹ Kim, J. M., Park, S. H., & Lee, J. (2017). Real-time monitoring of adenosine using an aptamer-based field-effect transistor biosensor. Biosensors and Bioelectronics, 89, 722-728. doi: 10.1016/j.bios.2016.10.014

² Huang, R., He, Y., Zhang, J., & Liu, B. (2015). Ultrasensitive, label-free, and real-time immunodetection of α-fetoprotein using silicon-based photonic crystal microcavities combined with aptamer amplification. Biosensors and Bioelectronics, 68, 499-504. doi: 10.1016/j.bios.2015.01.051

³ Wang, Y., Wu, J., Guo, J., & Liu, H. (2019). An aptamer-based biosensor for the detection of E. coli using fluorescence polarization. Analytical methods, 11(5), 676-680. doi: 10.1039/c8ay02634b