Acceleration effect of the forensic luminol reaction induced by visible light irradiation of whole human blood aqueous solutions. (June 2019)

• Record Type: Journal Article
• Authors: Hayashi, Saaya; Kakizaki, Eiji; Sonoda, Ai; Shinkawa, Norihiro; Shiragami, Tsutomu; Yukawa, Nobuhiro
• Is Part Of: Forensic science international. Volume 299(2019)
• Page Start: 208
• Page End: 214
• Publication Date: 2019-06
• Subjects: Luminol reaction -- Hemoglobin -- Human whole blood -- Visible light irradiation -- Chemiluminescence -- Singlet oxygen molecule; Medical jurisprudence -- Periodicals; Chemistry, Forensic -- Periodicals; Forensic Medicine -- Periodicals; Médecine légale -- Périodiques; Chimie légale -- Périodiques; Gerechtelijke geneeskunde; Gerechtelijke chemie; Gerechtelijke psychiatrie; Chemistry, Forensic; Medical jurisprudence; Electronic journals; Periodicals; Electronic journals; 614.1
• DOI: 10.1016/j.forsciint.2019.04.007
• Languages: English
• ISSNs: 0379-0738

Abstract

Highlights: The quantitative study on the effect of visible light on the luminol reaction. Irradiation with visible light increased the maximum chemiluminescence intensity. No conversion from Fe(II) hemoglobin to methemoglobin occurred during irradiation. The acceleration effect is likely induced by 1 O2, generated from an excited heme. Abstract: The first quantitative study on the effect of visible light irradiation on the luminol reaction, used forensically, was conducted using whole human blood aqueous solutions (hemolytic state) and an LED lamp. Whole human blood aqueous solutions under an air atmosphere were irradiated with visible light, resulting in the maximum chemiluminescence (CL) intensity (@ 440 nm) increasing about 1.7-fold due to acceleration of the luminol reaction rate. No acceleration effect was observed under an argon (Ar) atmosphere, or under an air atmosphere in the presence of sodium azide (NaN3 ; a scavenger of singlet oxygen ( 1 O2 )). Furthermore, no conversion from Fe(II) hemoglobin to Fe(III) hemoglobin (methemoglobin) was observed in the absorption spectrum following irradiation. We suggest that these effects are due to easier approach of the luminol reagents to heme following damage of the globin protein around the heme, or damage to the red blood cell membrane, induced by 1 O2 generated by an excited state of heme.