Confined-domain crosslinking-enhanced electrochemiluminescence of amino-acid-derived carbonized polymer dots for sensitive bioanalysis.

Tryptophan/arginine-derived carbonized polymer dots were synthesized to reveal confined-domain crosslinking-enhanced photoluminescence (PL) and electrochemiluminescence (ECL). Structural, electrochemical, and in situ spectroscopic studies assign blue PL to confined high-energy molecular/sub-domain states and near-infrared ECL to electrochemically populated surface/interfacial states, enabling sensitive alpha-fetoprotein biosensing without additional amplification.