Power-response fingerprinting reveals probe-dependent scaling and a productivity-efficiency trade-off in a high-frequency sonoreactor

Chemical dosimetries are widely used to characterize acoustic cavitation, yet their signals are often treated as interchangeable measures of a single radical yield. The unresolved question is whether differences among these signals remain as fixed assay-specific offsets or change systematically when acoustic power is varied. Here, power-response fingerprinting (PRF) is introduced as a probe-aware framework for comparing how chemically distinct reporters respond to the same calorimetrically measured power perturbation. At 585 kHz, the dissipated acoustic power was 9.65, 38.0, and 79.0 W, and the corresponding responses were quantified using potassium iodide (KI/I 3 − ), hydrogen peroxide (H 2 O 2 ), Fricke (Fe3⁺), and 4-nitrophenol hydroxylation to 4-nitrocatechol (4-NC). An 8.19-fold increase in calorimetric power increased the formation rates by only 5.13-fold for KI, 5.67-fold for H 2 O 2 , 3.06-fold for Fricke, and 3.12-fold for 4-NC, giving descriptive global power exponents of 0.74, 0.80, 0.49, and 0.51, respectively. Energy normalization revealed a complementary productivity-efficiency trade-off: at 79 W, the responses per joule retained only 0.63, 0.69, 0.37, and 0.38 of their 9.65 W values, and the largest decrease occurred between 9.65 and 38 W. At the common high-power generator setting, Ar increased H 2 O 2 accumulation to 1.88 times the unsparged-water rate, whereas N 2 reduced it to 0.16 times that rate. The matched response vector therefore shows that acoustic power changes the relative expression of measurable sonochemical channels rather than uniformly amplifying a universal cavitation output. PRF separates chemical productivity from energy-specific performance without treating chemically different assays as stoichiometrically equivalent.