Wireless Enantioselective Bipolar Electrocatalysis: Visual Quantification of Chiral Tryptophan via Kinetic pH‐Transduction

Rapid, decentralized determination of enantiomeric excess (ee) remains a critical challenge in sustainable chemical analysis. In this study, we report a wireless bipolar electrocatalytic platform that translates microscopic chiral recognition events into macroscopic quantifiable signals. Utilizing a graphite bipolar electrode (BPE) modified with an enantiopure tetrathiahelicene (7TH-S) polymer, we achieve the kinetic discrimination of tryptophan (Trp) enantiomers. The polymer film functions as a robust heterogeneous chiral electrocatalyst, exhibiting pronounced enantioselectivity with a substantial oxidation potential difference (ΔE ∼ 200 mV) and a markedly enhanced exchange current density (j0) for the matched enantiomer. This anodic catalytic turnover rate strictly governs the electron flux to the cathodic pole, thereby modulating the kinetics of water reduction and the resulting size of a pH-induced colorimetric halo. This mechanism enables the direct translation of molecular chirality into a geometric readout. We demonstrate a precise, linear correlation (R2 > 0.999) between the colorimetric halo dimension and the ee of Trp mixtures, validated by high chemoselectivity against interferents and quantitative recovery in real pharmaceutical samples. By eliminating the need for bulky instrumentation and minimizing solvent consumption, this frugal system offers a highly sensitive and sustainable alternative to conventional chromatographic techniques, aligning with the principles of responsible chemical science.