Description
Surface-functional biosensor recognition ligand designed for selective detection of Cardiac Troponin I (cTnI), supplied as a thiol-modified DNA aptamer for direct immobilization on gold and thiol-reactive sensor surfaces. Engineered for controlled orientation, high binding specificity, and stable integration into electrochemical and microfluidic biosensor platforms. For Research Use Only (RUO).
Product Description
The ProbeSeq Cardiac Troponin I BiosensorProbe™ is a thiol-functionalized DNA aptamer engineered for selective recognition and capture of cardiac troponin I (cTnI), a highly specific biomarker of myocardial injury and acute coronary syndromes. The probe incorporates a terminal sulfhydryl (–SH) functional group enabling controlled covalent attachment to gold and thiol-reactive sensor interfaces while preserving aptamer folding and target-binding activity.
Cardiac troponin I is a regulatory protein (~24 kDa) involved in calcium-mediated cardiac muscle contraction and is released into circulation following myocardial cell damage. Due to its high tissue specificity and low baseline concentration in healthy individuals, cTnI is widely used for early detection of myocardial infarction and cardiac injury. The BiosensorProbe™ is optimized for surface-immobilized sensing environments, enabling dense probe packing, controlled orientation, and stable signal generation across electrochemical, optical, and impedance-based detection platforms.
Recognition Mechanism
Target recognition is mediated by a sequence-engineered single-stranded DNA aptamer that undergoes conformational folding upon interaction with structural domains of cardiac troponin I. Binding occurs through electrostatic interactions, hydrogen bonding, and molecular shape complementarity. The conformational transition upon target binding produces stable surface-associated complexes suitable for label-free and signal-amplified detection.
The aptamer maintains structural integrity following immobilization and provides reversible yet stable binding kinetics suitable for quantitative biosensing.
Specificity and Selectivity
The Cardiac Troponin I BiosensorProbe™ demonstrates high molecular specificity toward cardiac troponin I with minimal cross-reactivity toward related muscle proteins such as troponin T, troponin C, myoglobin, and creatine kinase. Sequence-driven recognition targets structural epitopes unique to cardiac isoforms, enabling selective detection in complex biological matrices including serum, plasma, and whole blood extracts.
High selectivity supports reliable performance in multiplex cardiac biomarker panels and reduces background signal from non-specific protein adsorption.
Molecular Format and Functionalization
The product consists of a synthetic single-stranded DNA aptamer containing a terminal thiol (–SH) functional group introduced through controlled chemical modification. The thiol group enables chemisorption onto gold surfaces and covalent coupling with thiol-reactive coatings through metal–sulfur bonding or maleimide–thiol reactions.
The probe is purified to high chemical purity and stabilized to preserve functional group reactivity, structural folding, and binding performance.
Surface Immobilization Chemistry
The terminal thiol group supports direct immobilization on gold electrodes through formation of self-assembled monolayers. The probe is compatible with nanostructured gold, planar gold electrodes, gold nanoparticles, and thiol-reactive polymer coatings.
Surface attachment enables controlled probe orientation, improved target accessibility, reduced probe desorption, and reproducible surface coverage. Immobilized probes maintain activity under standard biosensor operating conditions and repeated assay cycles.
Compatible Sensor Surfaces
Gold electrodes and nanostructured gold substrates
Gold nanoparticle-modified interfaces
Thiol-reactive polymer coatings
Maleimide-functionalized surfaces
Electrochemical impedance and amperometric sensors
Microfluidic lab-on-chip platforms
Surface plasmon resonance gold chips
Performance Characteristics
High specificity toward cardiac troponin I
Low non-specific adsorption on sensor surfaces
Stable immobilization on gold substrates
Preserved aptamer folding after surface coupling
Reproducible binding performance in serum and buffer matrices
Suitable for label-free and signal-amplified detection systems
Stability
The Cardiac Troponin I BiosensorProbe™ is chemically stabilized to maintain aptamer conformation and thiol reactivity under recommended storage and operating conditions. The DNA aptamer structure provides resistance to temperature variation, moderate pH changes, and repeated assay cycles following immobilization. Surface-bound probes demonstrate stable binding performance under physiological ionic strength.
Storage
Store at −20°C in the supplied buffered formulation. Avoid repeated freeze–thaw cycles and prolonged exposure to oxidizing environments to preserve thiol functionality. Under recommended storage conditions, the product is stable for at least 12 months from the date of receipt.
Applications
Electrochemical cardiac biomarker sensing
Point-of-care myocardial injury detection
Acute coronary syndrome research
Surface plasmon resonance assays
Microfluidic diagnostic device development
Wearable cardiac monitoring systems
Multiplex cardiac biomarker panels
