Abstract:
This study investigated isatin as a potential fingermark enhancement reagent for use on porous surfaces. A number of parameters were investigated, including concentration, solvent system, pH of the solution, and optimization of the development conditions. It was determined that isatin at a concentration of 0.05% (w/v) provided the optimum balance between the luminescence of the fingermark ridges and background. A carrier solvent of dioxane mixed with acetone [12.5% (v/v)] produced the most intense luminescence. It was determined that the optimum pH for the development of fingermarks was 5.0 and that this could be reached by the addition of 4% (vlv) sodium carbonate buffer. The use of a dry heat press at 180°C for 10 s provided optimal development conditions.