Description
Surface-functional biosensor recognition ligand designed for selective detection of Hemoglobin A1c (HbA1c), supplied as a thiol-modified DNA aptamer for direct immobilization on gold and thiol-reactive sensor surfaces. Engineered for high binding specificity, controlled probe orientation, and stable integration into electrochemical and microfluidic biosensor platforms. For Research Use Only (RUO).
Product Description
The ProbeSeq Hemoglobin A1c BiosensorProbe™ is a thiol-functionalized single-stranded DNA aptamer engineered for selective recognition and capture of HbA1c, a glycated form of hemoglobin widely used as a long-term indicator of blood glucose levels and diabetes management. The probe incorporates a terminal sulfhydryl (–SH) functional group enabling stable covalent immobilization on gold sensor interfaces while preserving aptamer folding and binding activity.
Hemoglobin A1c is formed through non-enzymatic glycation of hemoglobin β-chain N-terminal residues and reflects average blood glucose levels over 8–12 weeks. HbA1c typically represents 4–6% of total hemoglobin in healthy individuals and ≥6.5% in diabetic patients. The BiosensorProbe™ supports quantitative detection across clinically relevant concentration ranges.
The probe enables high-density surface immobilization (~10¹²–10¹³ molecules/cm²), controlled probe orientation, and stable signal generation across electrochemical, impedance, and optical sensing platforms.
Recognition Mechanism
Target recognition is mediated by a sequence-engineered single-stranded DNA aptamer (~45–80 nucleotides) that selectively binds glycated hemoglobin epitopes through hydrogen bonding, electrostatic interactions, and structural complementarity.
Binding affinity (Kd): 0.1–5 nM
Detection range: %HbA1c equivalent or ng/mL–µg/mL depending on assay format
Association kinetics: seconds to minutes
Reversible binding suitable for quantitative monitoring
Specificity and Selectivity
The HbA1c BiosensorProbe™ demonstrates high specificity toward glycated hemoglobin with minimal cross-reactivity toward non-glycated hemoglobin (HbA0) and other blood proteins.
Cross-reactivity: <5% against non-glycated hemoglobin
Non-specific adsorption reduction: >90% vs non-functionalized DNA
Matrix compatibility: whole blood lysates, serum, and plasma
Molecular Format and Functionalization
Synthetic single-stranded DNA aptamer containing terminal thiol functional group.
Aptamer length: ~45–80 nucleotides
Functionalization efficiency: ≥95% thiol incorporation
Purity: ≥95% (HPLC verified)
End modification: 5′ C6-thiol linker
Buffer formulation: nuclease-free buffered solution
Surface Immobilization Chemistry
Terminal thiol enables self-assembled monolayer formation on gold surfaces via Au–S bonding.
Surface binding strength: ~40–50 kcal/mol
Immobilization time: 30–120 min
Recommended surface density: 1–10 pmol/cm²
Operating pH after immobilization: 6.5–8.5
Compatible Sensor Surfaces
Gold electrodes and nanostructured gold substrates
Gold nanoparticle-modified interfaces
Thiol-reactive polymer coatings
Maleimide-functionalized surfaces
Electrochemical biosensors
Microfluidic diagnostic devices
Wearable glucose monitoring platforms
Performance Characteristics
Binding affinity: 0.1–5 nM
Surface coverage: 10¹²–10¹³ molecules/cm²
Operating temperature: 4–45°C
Low non-specific adsorption
Stable signal response during repeated measurement
Stability
Shelf stability: ≥12 months at −20°C
Working stability after immobilization: ≥14 days
Thermal tolerance: stable up to ~60°C short exposure
Storage
Store at −20°C in supplied buffer. Avoid repeated freeze–thaw cycles. Protect from oxidation and light.
Applications
Diabetes monitoring research
Long-term glucose regulation studies
Electrochemical biosensor development
Point-of-care metabolic diagnostics
Wearable health monitoring devices
Microfluidic diagnostic systems
