A label-free sensitive method for membrane protein detection based on aptamer and AgNCs transfer

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• Membrane proteins are crucial in physiological processes and are investigated as cancer biomarkers and drug targets.
• Accurate detection of membrane proteins on living cells is vital for cancer research and clinical applications.

Purpose of the Study:

• To develop a facile, sensitive, and quantitative method for detecting membrane proteins on living cells in situ.
• To validate the method's utility for identifying potential cancer biomarkers.

Main Methods:

• A novel detection strategy based on membrane protein-triggered release of cytosine-rich single-stranded DNA (ssDNA).
• Subsequent silver nanocluster (AgNCs) transfer to ssDNA, forming fluorescent DNA-AgNCs for detection.
• Utilized a common fluorescence spectrophotometer for quantitative analysis.

Main Results:

• Demonstrated a sensitive detection method for membrane proteins with a high quantum yield and stable DNA-AgNCs.
• Successfully detected protein tyrosine kinase-7 (PTK7) with a response range from 30pM to 2nM and a detection limit of 12pM.
• Quantified PTK7 expression on single Hela and CCRF-CEM cells, confirming the method's sensitivity.

Conclusions:

• The developed method provides a universal and ultrasensitive platform for in situ detection of membrane proteins on cells.
• This facile detection strategy holds significant potential for cancer biomarker discovery and clinical validation.