Objective

1) Overview

• The traditional systematic evolution of ligands by exponential enrichment (SELEX) process is time-consuming and imperceptible 

2) Scientific Specialty and Levels

• Gold nanoaprticle-facilitated assembly via supernatant transfer (GNP-FAST) combined with GNP-SELEX is proposed as a visual and straightforward monitoring platform for the rapid discovery of small molecule-binding single-stranded DNA (ssDNA) aptamers

3) Expected Contributions & Future Direction

• A colorimetric SELEX platform will facilitate the rapid discovery of ssDNA aptamers against various targets and identify their wide applications in biosensing and bioassays

4) Related References

•   Biosens. Bioelectron. 2021, 191, 113468

•   Chemosensors 2021, 9(3), 54

•   Chemosphere 2019, 228, 110

•   Sensors and Actuators B-Chemical 2018, 260, 371

•   Sensors and Actuators B-Chemical 2018, 256, 89

•   Sensors 2017, 17(12), 2840

•   Sensors 2014, 14(10), 18302

1) Overview

• Despite the therapeutic potential of recombinant proteins, their cell permeabilities and stabilities remain significant challenges. Cyclized recombinant proteins can be used as universal cargos for permeable and stable delivery into cells, liposomes, and EVs.

2) Scientific Specialty and Levels

• Cyclization of proteins for delivery into cells, liposomes, and exosomes

• In silico simulation for membrane penetration

3) Expected Contributions & Future Direction

• This strategy will be universally applicable to intercellular delivery of proteins and EVs for therapy

4) Related References

• International Journal of Biological Macromolecules 2023, 252; 126520

• International Journal of Molecular Sciences 2022, 23(3), 1605

1) Overview

• To address the challenge of faint fluorescence (FL) in cell surface-targeted diagnostics, we propose an APEX2-driven proximity imaging technique and a ligand-driven enzyme-accelerated signal enhancement (L-EASE) technique to clearly visualize cancer cells or EVs.

2) Scientific Specialty and Levels

• Cyclization of proteins for labeling and imaging in cells and EVs

• Enzyme-mediated signal amplification

3) Expected Contributions & Future Direction

• These methods will be useful as a universal visualization method with exceptional sensitivity and usability for detecting cancer cells and EVs.

4) Related References

• International Journal of Biological Macromolecules 2023, 252; 126520

• International Journal of Molecular Sciences 2022, 23(3), 1605

1) Overview

• A subset of cell-secreted proteases are implicated in a wide range of biological processes in normal and pathological events. For example, activity-based assays of matrix metalloproteinases (MMPs) is a key issue to understand their contributions to tumor progression.

• Fluorescence or bioluminescence resonance energy transfer (FRET or BRET) systems between biomolecules and/or nanoparticles bring new insight to detect biomolecular change with higher sensitivity and flexibility.

2) Scientific Specialty and Levels

• Although expression profiles of cell-secreted proteases have been reported to be useful in explicating various disease processes, a practical issue in quantifying levels of protease activities in clinical samples remains formidable because only difference in total expression where the correlation might not necessarily be related to disease level. Therefore, emphasis should be placed on the importance of active proteases rather than their expression levels in tumor.

• Our designed probes include the sensing part (peptide substrate) and detection part (fluorescence, bioluminescence and/or their energy transferred couplers). Nanoparticles (gold, quantum dot, or polymer-based nanoparticles) have been combined with this system to enhance the sensitivity and other optical properties. This nanohybrid probe can serve as a biosensor and/or an imaging probe for targeting active proteases.

3) Expected Contributions & Future Direction

• Protease-related cancer metastasis study based on in vivo diagnostic/imaging of protease activity

• Protease activity profiling to address biological function of proteases in vitro and in vivo

4) Related References

• ACS Sensors 2020, 5(3), 655

• Sensors and Actuators B-Chemical 2019, 281, 527

• Sensors 2018, 18(3), 875

• Theranostics 2012, 2(2), 127

• Chem. Commun. 2010, 46, 76

• Biosens. Bioelectron. 2009, 24(5), 1189

• Anal. Chem. 2008, 80(13), 5094

• Anal. Chem. 2008, 80(12), 4634

1) Overview

• Gold nanoparticle-based colorimetric biosensors for assaying enzyme activity 

• CRISPR-based diagnostics

• FRET/BRET-based biosensors

• ROS Biosensors using DNA-Protein interactions

2) Scientific Specialty and Levels

• Complicate methods are formidable for the development of biosensors.

• There is still a challenge in enhancing FRET/BRET efficiency to avoid high background noise signal. 

• Despite the implications of rapid influx and oxidation of free LMW biothiols in plasma, current methods are neither sufficiently convenient nor rapid enough to detect free LMW biothiols because free LMW biothiols are susceptible to rapid oxidation.

3) Expected Contributions & Future Directions

• Colorimetric assays using gold nanoparticles (AuNPs) is valuable for determining the physiological roles of many protein activities in a rapid and simple way.

• QD-FRET/BRET method is anticipated to facilitate applications for studying physiological functions of protein kinases in association with drug development.

• We report a novel method for the rapid detection of plasma LMW biothiols using a bacterial redox-sensing transcription repressor protein and its operator DNA element.

4) Related References

• Sensors and Actuators B-Chemical 2021, 336, 129735

• Analytical Chemistry 2019, 91(15), 10064

• Sensors and Actuators B-Chemical 2017, 246, 271

• ChemBioChem 2016, 17(4), 275

• Sensors 2015, 15(8), 17977

• Analytical Chemistry 2015, 87(2), 1257

• Biosensors & Bioelectronics 2012, 41(1), 833

• Biosensors & Bioelectronics 2012, 41(1), 752

1) Overview

• Microfluidic or mass spectrometric biochips for assaying kinase activity and screening inhibitory drugs

• Fluorescence biochips for monitoring cancer biomarkers in conjuction with nanostructures

• Microfluidic biochips for determining protein-DNA interactions

• Colorimetric biochips for screening ROS scavengers

2) Scientific Specialty and Levels

• Most studies to assay enzyme activity and their inhibitors have relied on labor-intensive and time-consuming techniques.

• Matrix-free time-of-flight secondary ion mass spectrometry (TOF-SIMS)-based biochips

• Based on the observation that secondary ion mass signal of peptides is highly enhanced on AuNPs, this system was applied to the assaying of kinase activity and its inhibition with high detection sensitivity (~fmol/mm2) of the mass change of peptide substrates in a kinase reaction.

• Microfluidic biochip for the detection of low-molecular-weight thiols

• Based on the protein (repressor)-DNA (binding element) interaction

• Microfluidic biochip for the detection of isoelectric points of proteins

3) Expected Contributions & Future Directions

• Therapeutic applications for drug development by screening various PTM-related enzymes and their inhibitors with high sensitivity in a high-throughput manner

4) Related References

• BioChip Journal 2020, 14, 148

• Sensors and Actuators B-Chemical 2018, 256, 89

• Anal. Chem. 2017, 89(1), 799

• Scientific Reports 2015, 5, 12019

• Small 2015, 11(28), 3469

• Biosens. Bioelectron. 2015, 73(1), 93

• Mass Spectrometry Reviews 2015, 34(2), 237

• Anal. Chem. 2006, 78, 1913

• Angew. Chem. Int. Ed. 2007, 46, 6816

• Biosens. Bioelectron. 2008, 23(7), 980