Rapid and colorimetric assay for the detection of S. pneumoniae based on hydrogen peroxide release and analysis using color image processing


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Celik Yoldas C., Temur N., Ildiz N., SAĞIROĞLU P., ATALAY M. A., Yilmaz A., ...Daha Fazla

Analyst, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1039/d5an01356a
  • Dergi Adı: Analyst
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, MEDLINE
  • Erciyes Üniversitesi Adresli: Evet

Özet

Although Streptococcus pneumoniae (S. pneumoniae) is routinely identified using various clinical methods, most existing techniques are complicated, time-consuming, and require expensive equipment. Consequently, there is a critical need for rapid, sensitive, and economical detection methods. Herein, we report a rationally designed colorimetric assay incorporating biocompatible anthocyanins for the rapid detection of S. pneumoniae via the naked eye and image processing software. Unlike conventional anthocyanin-based assays that rely on pH-dependent color changes, our approach uses anthocyanins as oxidative degradation probes rather than pH indicators. The detection mechanism relies on the oxidative degradation of anthocyanins by hydrogen peroxide (H2O2), a key virulence factor secreted by S. pneumoniae, which induces a distinct color shift to gray. We systematically evaluated the performance of this assay in various matrices, including growth medium, saline solution, and artificial cerebrospinal fluid (aCSF). Bacterial suspensions of 1.0 and 1.5 McFarland were colorimetrically detected within 90 and 30 minutes, respectively, through naked-eye observation and Delta-E analysis. This study demonstrates a highly stable, cost-effective, and easy-to-prepare diagnostic tool that offers significant advantages over traditional methods for point-of-care testing.