Single-Entity Current-Blockade Electrochemistry at a Polypyrrole-Bromocresol Purple-Modified Carbon Ultramicroelectrode for Rapid Albumin Quantification

Öz

Albumin is the predominant plasma protein and a clinically relevant marker used in the assessment of liver synthetic function, renal protein loss, nutritional status and fluid balance. This experimental proof-of-concept study reports a rapid albumin-sensing strategy based on single-entity current-blockade electrochemistry using a polypyrrole/bromocresol purple-modified carbon ultramicroelectrode (C-UME-PPy-BCP). The C-UME was modified by cyclic voltammetric electropolymerization in acetonitrile containing 1 mM pyrrole, 500 µM bromocresol purple and 0.1 M LiClO4. Electrode modification was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy in a ferri/ferrocyanide redox-probe solution. Albumin-dependent chronoamperometric measurements produced transient negative current-blockade events arising from short-lived interactions of albumin with the modified microelectrode interface. Event-frequency calibration was linear over 0.1-10 g/dL albumin, with a slope of 8.25 events min-1 per g/dL, R2 = 0.9951 ± 0.0005, an estimated LOD of 0.06 g/dL and an LOQ of 0.18 g/dL. Replicate calibration, matrix recovery, interferent-response and short-term stability experiments further supported the analytical feasibility of the C-UME-PPy-BCP platform. Recoveries ranged from 96.1 to 98.4%, relative standard deviations remained below 6%, and common interferents produced limited relative responses compared with albumin. The findings support single-entity current-blockade electrochemistry as a rapid microscale approach for albumin quantification with established dye-binding or immunochemical albumin assays.

Anahtar Kelimeler

• albumin
• single entity electrochemistry
• polipyrrole
• bromocresol purple
• sensor
• biosensor

Polipirol-Bromokrezol Moru ile Modifiye Karbon Ultramikroelektrotta Hızlı Albümin Kantifikasyonu için Tekil-Varlık Akım-Blokaj Elektrokimyası

Öz

Albümin, karaciğer sentez kapasitesi, renal protein kaybı, beslenme durumu, inflamasyon yükü ve sıvı dengesi ile ilişkili temel bir klinik biyokimya belirtecidir. Bu deneysel kavram kanıtlama çalışmasında, polipirol/bromokrezol moru ile modifiye edilmiş karbon ultramikroelektrot (C-UME-PPy-BCP) kullanılarak tekil-varlık akım-blokaj elektrokimyasına dayalı hızlı bir albümin tayin stratejisi sunulmuştur. C-UME yüzeyi, 1 mM pirol, 500 µM bromokrezol moru ve 0.1 M LiClO4 içeren asetonitril ortamında döngüsel voltametrik elektropolimerizasyon ile modifiye edilmiştir. Elektrot modifikasyonu, ferri/ferrosiyanür redoks prob çözeltisinde döngüsel voltametri ve elektrokimyasal empedans spektroskopisi ile değerlendirilmiştir. Albümine bağlı kronoamperometrik ölçümler, modifiye mikroelektrot arayüzüyle kısa süreli albümin etkileşimlerinden kaynaklanan geçici negatif akım-blokaj olayları üretmiştir. Olay frekansına dayalı kalibrasyon 0.1-10 g/dL aralığında doğrusal bulunmuş, LOD 0.06 g/dL ve LOQ 0.18 g/dL olarak hesaplanmıştır. Tekrarlı kalibrasyon, matris geri kazanımı, interferan yanıtı ve kısa dönem stabilite deneyleri, C-UME-PPy-BCP platformunun analitik uygulanabilirliğini desteklemiştir. Geri kazanım değerleri %96,1-98,4 aralığında bulunmuş ve bağıl standart sapmalar %6'nın altında kalmıştır.

Anahtar Kelimeler

• albümin
• tek varlık elektrokimyası
• polpirol
• brom krezol moru
• sensör
• biyosensör

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