An Improved Low‐Cost Screen‐Printed Biosensor Array for Sensitive and Precise Creatinine Detection

Creatinine is a critical biomarker of renal function. This study presents a creatinine biosensor array (CBA) based on screen‐printed carbon electrodes fabricated on PET substrates using admittance detection. Three configurations (1 × 1, 1 × 2, and 1 × 3) were evaluated over a creatinine concentration range of 50–250 μM. All configurations exhibited a linear response with R 2 values of 0.9170, 0.9508, and 0.9521 for 1 × 1, 1 × 2, and 1 × 3, respectively. At a common frequency of 10 900 Hz, the 1 × 3 configuration achieved 3‐fold higher sensitivity and 23% improvement in signal‐to‐noise ratio (SNR: 0.864 vs 0.791) compared to the 1 × 1 design. The 1 × 3 array also demonstrated an expanded linear frequency range (14 100 Hz–1 MHz) compared to the 1 × 1 (5640–7340 Hz). The sensitivity enhancement is attributed to increased enzymatic reaction capacity through series‐connected sensing windows. The developed CBA covers both physiological (50–110 μM) and pathological (>110 μM) creatinine ranges, providing a low‐cost platform for renal function assessment.