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• Ranibizumab is sold under trade name Lucentis and is used for treating macular degeneration and is very expensive drug, though it is produced in bioreactor. • Reason being no process analytical technique available for its online/inline monitoring for yield optimization. • We are for the first time generated aptamers for this analyte and developed an impedimetric sensor for its detection. • The aptamer was generated using modified SELEX process with good specificity (Kd in nM range) and selectivity. • A microfluidic chip was designed with immobilized aptamer for impedimetric label free detection of Ranibizumab in inline mode from a bioreactor. • The device showed low LOD, excellent selectivity and specificity for Ranibizumab without the need of sample pretreatment and preconcentration. • The detection time was just 30 min compared to several hours needed with HPLC based method. • Our sensing technique shall also be helpful to similar PAT control of bioproduction if aptamers/affinity agent for those analytes are generated/known. We have developed an aptamer based microfluidic chip for inline monitoring of Ranibizumab in bioreactors. Aptamers for Ranibizumab were generated using 10 rounds of the SELEX process. Two of the aptamers exhibited high affinity towards the target analyte with a dissociation constant within 20–30 nM range. The one with best affinity towards analyte was immobilized on gold micro-electrodes on a microfluidic chip, which was fabricated with glass base and PDMS top using conventional photolithographic technique. Immobilization steps were characterized using FTIR and EIS. Non-faradaic EIS measurement was used for label-free detection of Ranibizumab. The linear range of detection and LOD were found to be 25−100 nM and 25 nM respectively, which was significantly better than HPLC based detection method (about 240 nM). Further, this microchip-based detection did not require sample preconcentration or preprocessing and as a result, the detection time was reduced to 30 min compared to several hours with HPLC. The proposed detection system was validated using real samples of culture broths and no interferences were observed. Statistical analysis confirmed the correlation between the microfluidic chip and HPLC based method. As the selected aptamer was found highly specific for Ranibizumab, it can also be used for purification of Ranibizumab in affinity columns. Therefore, commercialization of this aptamer and microfluidic chip could have a significant impact on purification, various steps during biopharmaceutical production (clone selection and process optimization) and inline detection of Ranibizumab. [ABSTRACT FROM AUTHOR]

Heart failure (HF) is emerging as a leading cause of death worldwide. Estimation of BNP levels is a routine diagnosis in these patients. However, in patients having high body-mass index (BMI), renal disease or in geriatric patients, BNP level is reported to be noisy and leads to incongruous conclusion. Thus, for better risk stratification among heart failure patients, it is imperative to look for a superior biomarker. In recent times, sST2 has shown promise as a biomarker. Identifying such biomarkers in peripheral blood of HF patients, need an affine and selective molecular recognition element. Thus, in the current study an aptamer (sS9_P) against sST2 was identified from an aptamer library. Systematic Evolution of Ligands through Exponential enrichment (SELEX) derived aptamer evinced role of its primer binding domains in maintaining its selectivity. This aptamer candidate demonstrated dissociation constant (Kd) in low nanomolar range, and the Limit of Detection (LOD) was ~4 ng. Circular dichroism confirms the formation of complex stem-loop like structure. The well characterized sS9_P aptamer was used in an Aptamer Linked Immobilized Sorbent Assay (ALISA) to detect sST2 level in patients' serum (n = 99). Aptamer sS9_P has shown significant discrimination to differentiate HF patients and healthy volunteers with a reasonable specificity (~83 %) with a modest sensitivity of ~64 %. While sST-2 antibody has shown poor specificity of ~44% but good sensitivity (~87%). The insight obtained from this study indicates that a combination of aptamer and antibody-based assay can be used to design a point-of-care assay for the rapid detection of HF patients in emergency settings. [ABSTRACT FROM AUTHOR]