Amine-Reactive Homopolymer · NHS Ester
Poly(NHSMA)
Also written PNHSMA, poly(N-hydroxysuccinimide methacrylate) | Homopolymer — every repeat unit is reactive
A homopolymer of N-hydroxysuccinimide methacrylate (NHSMA), where every repeat unit carries an active NHS ester ready to react with primary amines. Rather than a functional comonomer blended into a matrix, this is a single-component reactive scaffold: react it once with an amine-bearing molecule — a protein, peptide, dye, drug, or amino-surface — and the NHS leaving group departs, leaving a stable amide bond in its place. It’s a standard precursor for post-polymerization modification (PPM) and one-step bioconjugation.
- Moisture-sensitive — shipped and stored desiccated
Polymer: batch-dependent
(C₈H₉NO₄)ₙ
Poly(NHSMA)
Appearance: White to off-white powder
Character: Amine-reactive (NHS ester)
Architecture: Homopolymer
Storage: -20 °C, dark, desiccated
ISO 9001:2015
Manufactured under certified quality management
Custom MPC Ratio
Sealed under inert, moisture-controlled conditions to protect reactivity
Batch-Level COA
Mn, Đ, and NHS-ester activity confirmation per lot
Sample to Bulk
Gram-scale R&D up to bulk supply
CAS No.
Polymer: batch-dependent
Molecular Formula
(C₈H₉NO₄)ₙ
Character
Amine-reactive (NHS ester)
Mn Range
8K – 100K
Form
Powder
One reactive handle, react it however you like
Every repeat unit carries the same NHS ester — the "functionalization" happens after polymerization, when you choose what amine to couple it to.
Amine-selective coupling
The NHS ester reacts specifically with primary amines (–NH₂) — on lysine side chains, amine-terminated PEGs, aminated surfaces, or small-molecule amines — forming a stable amide bond.
One scaffold, many products
Because every unit is identically reactive, a single batch of Poly(NHSMA) can be split and coupled to different amines to generate a whole library of functional polymers.
Mild, fast reaction conditions
Coupling proceeds at room temperature in aqueous or organic buffer within minutes to a few hours — no catalyst or activation step needed, unlike carboxylic acid coupling chemistries.
Water is the competing reaction
Hydrolysis of the NHS ester back to a carboxylic acid competes with amine coupling, and speeds up as pH rises — which is why timing and buffer choice matter.
Most protocols target pH 7.5–8.5 in an amine-free buffer (avoid Tris, glycine, or other primary-amine buffers, which compete for the ester). Work on ice and react promptly once the polymer is dissolved — dissolved NHS ester hydrolyzes continuously, even before your intended amine is added.
Values below are representative for this monomer. Batch-specific COAs with GPC and NHS-ester activity data are available on request.
Chemical Name | Poly(N-hydroxysuccinimide methacrylate) |
|---|---|
| Synonyms | PNHSMA · Poly(NHS methacrylate) · Poly(methacrylic acid NHS ester) · Reactive ester homopolymer |
| Repeat Unit | N-hydroxysuccinimide methacrylate (NHSMA) |
| Architecture | Linear homopolymer — every repeat unit is an NHS ester |
| Reactive Group | N-hydroxysuccinimide (NHS) active ester, reacts with primary amines |
| CAS Number (polymer) | Not applicable — Mn and dispersity are set per synthesis batch |
| Molecular Weight (Mn) | Custom synthesis, typically 8,000–100,000 g/mol |
| Dispersity (Đ) | 1.1–1.3 (RAFT/ATRP) · broader for free-radical routes |
| Appearance | White to off-white powder |
| Solubility | DMF, DMSO, THF, dioxane; limited aqueous solubility due to hydrolysis |
| Reactivity Note | Hydrolytically unstable in water — dissolve and react promptly; avoid primary-amine buffers |
| Storage | Sealed, desiccated, −20 °C, protected from light and moisture |
Need a specific Mn, or the polymer pre-coupled to a target amine? Talk to technical sales →
Choose the Mn that fits your conjugate
Because every repeat unit is reactive, chain length directly sets how many coupling sites (or how large a resulting graft) each polymer chain carries.
Mn ≈ 8,000–20,000
Low MW
Fewer reactive sites per chain — suited to discrete, well-defined small-molecule or single-protein conjugates.
Mn ≈ 20,000–50,000
Medium MW
A common general-purpose range for PPM libraries and multivalent bioconjugates with moderate coupling density.
Mn ≈ 50,000–100,000
High MW
Maximum reactive-site density per chain — favored for dense surface functionalization and multivalent coatings.
Applications
Protein-polymer conjugates
Couples directly to lysine amines on proteins and peptides in one step, without an activation reagent.
Post-polymerization modification (PPM)
The classic "activated ester" strategy — synthesize one reactive precursor, then split it into a library of differently functionalized polymers.
Surface bioconjugation
Coupled to amine-functionalized substrates, beads, or chips to immobilize biomolecules for assays and biosensors.
DNA / oligonucleotide conjugation
Reacts with 5′- or 3′-amine-modified oligonucleotides to build polymer-DNA hybrids for diagnostics and nanotechnology.
Drug-polymer conjugates
Attaches amine-bearing small-molecule drugs directly to the polymer backbone for prodrug or delivery constructs.
Amine-crosslinked hydrogels
Reacting with a diamine or multi-amine crosslinker converts the linear reactive polymer into a covalent hydrogel network.
Antibody & peptide immobilization
A common route for microarray and biosensor surfaces that need oriented, covalent capture of antibodies or peptides.
Fluorescent / affinity tagging
Couples amine-functionalized dyes, biotin, or affinity handles onto the polymer backbone for labeling and detection.
Data & safety documents
Batch-specific COAs with GPC and NHS-ester activity data available for order confirmations. Contact us for a specific lot number.
Safety Data Sheet
GHS-format · EN / ZH
Certificate of Analysis
Ratio + Mw confirmation
Amine Coupling Protocol
Recommended buffers & conditions
FAQ
Most frequent questions and answers
It’s a reactive precursor polymer — every repeat unit carries an NHS ester that reacts with primary amines. It’s used for one-step protein-polymer conjugation, post-polymerization modification (PPM) to build polymer libraries, surface bioconjugation, DNA/oligo conjugation, and drug-polymer conjugates.
A primary amine (R-NH₂) attacks the activated carbonyl of the NHS ester, forming a stable amide bond between the polymer and your amine-bearing molecule, while N-hydroxysuccinimide is released as a small-molecule byproduct.
Not indefinitely — water is a competing nucleophile, and the NHS ester slowly hydrolyzes back to a carboxylic acid once dissolved in aqueous buffer, faster at higher pH. For best coupling yields, dissolve it fresh and react promptly with your amine, rather than pre-dissolving and storing the solution.
As supplied, it’s the unreacted reactive precursor — it will not have the properties of your final target material until you couple it to an amine. Think of it as a blank scaffold: react it with the amine of your choice to obtain the functional polymer you actually want.
Most protocols use pH 7.5–8.5 buffers (e.g. phosphate or bicarbonate) that don’t themselves contain primary amines — avoid Tris and glycine buffers, which compete for the ester. Work cold, use freshly dissolved polymer, and add your amine-bearing target promptly.
N-hydroxysuccinimide is released as a small, water-soluble byproduct once the amide bond forms. It’s typically removed from the conjugate by dialysis, size-exclusion chromatography, or ultrafiltration during workup.
The polymer itself is not assigned a single CAS Registry Number, since Mn and dispersity are set per synthesis batch — this is standard for custom-synthesized polymers. Each lot’s COA documents the measured molecular weight and NHS-ester activity.
Store sealed, desiccated, at −20 °C, protected from light and moisture — the NHS ester is sensitive to both heat and humidity. Allow the container to reach room temperature before opening to avoid condensation, and use freshly opened/dissolved material for best coupling efficiency.