Ultrasensitive and Selective Protein Recognition with Nanobody-Functionalized Synthetic Nanopores

• The development of flexible and reconfigurable sensors that can be readily tailored toward different molecular analytes constitutes a key goal and formidable challenge in biosensing. In this regard, synthetic nanopores have emerged as potent physical transducers to convert molecular interactions into electrical signals. Yet, systematic strategies to functionalize their surfaces with receptor proteins for the selective detection of molecular analytes remain scarce. Addressing these limitations, a general strategy is presented to immobilize nanobodies in a directional fashion onto the surface of track-etched nanopores exploiting copper-free click reactions and site-specific protein conjugation systems. The functional immobilization of three different nanobodies is demonstrated in ligand binding experiments with green fluorescent protein, mCherry, and α-amylase (α-Amy) serving as molecular analytes. Ligand binding is resolved using a combination of optical and electrical recordings displaying quantitative dose–response curves. Furthermore, a change in surface charge density is identified as the predominant molecular factor that underlies quantitative dose–responses for the three different protein analytes in nanoconfined geometries. The devised strategy should pave the way for the systematic functionalization of nanopore surfaces with biological receptors and their ability to detect a variety of analytes for diagnostic purposes. © 2021 The Authors. Small published by Wiley-VCH GmbH

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

biosensors

current rectification

molecular diagnostics

nanobodies

nanofluidic devices

synthetic nanopores

track-etched membrane

Ligands

Nanopores

Biological receptors

Electrical recording

Green fluorescent protein

Protein conjugations

Protein recognition

Reconfigurable sensors

Selective detection

Proteins

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)