TruFluor pH Single-Use Sensor

Overview

The Thermo Scientific™ TruFluor pH Single-Use Sensor is an optically based, fluorescence-quenching pH sensing device engineered for real-time, non-invasive monitoring in single-use bioprocessing systems. Unlike traditional glass-electrode or ISFET-based online pH meters, the TruFluor sensor employs solid-state fluorophore immobilization within a chemically stable hydrogel matrix, enabling robust and drift-free measurement across the physiologically relevant pH range (5.0–8.0). Its operation relies on dynamic quenching of fluorescent emission intensity by hydrogen ions—a principle rooted in Förster resonance energy transfer (FRET) and Stern–Volmer kinetics—ensuring high specificity, minimal photobleaching, and immunity to electrochemical interference. Designed exclusively for integration into Thermo Scientific single-use bioreactors (e.g., HyPerforma™ and S.U.B. platforms), the sensor is permanently welded to the vessel’s optical window, eliminating fluidic interfaces, calibration drift, and cleaning validation burdens associated with reusable probes.

Key Features

• Optical fluorescence-based pH detection with no electrical contact or electrolyte leakage risk
• Pre-calibrated at manufacture; factory traceable to NIST-traceable pH buffer standards
• USP Class VI compliant polymer housing—fully extractables- and leachables-tested per ICH Q5A and Q5B guidelines
• Animal-component-free construction: no bovine serum albumin (BSA), collagen, or porcine-derived reagents used in sensor fabrication
• Integrated with TruFluor 316L stainless steel thermal and mass-transfer optical window for minimized thermal lag and enhanced signal-to-noise ratio
• Compatible with Thermo Scientific iC32 and BioCommand™ process control software for automated data logging and alarm configuration

Sample Compatibility & Compliance

The TruFluor pH sensor is validated for use in mammalian, microbial, and stem cell culture processes operating under standard bioreactor conditions (37 °C, 0–100% dissolved oxygen saturation, agitation 50–200 rpm). It exhibits negligible protein fouling due to its hydrophilic, low-binding surface chemistry and demonstrates stability across common cell culture media (e.g., DMEM, RPMI-1640, TB, and chemically defined formulations). Regulatory compliance includes adherence to ISO 13485:2016 (medical device quality management), ASTM E2656-20 (standard guide for optical biosensors), and alignment with FDA 21 CFR Part 11 requirements when deployed with compliant software architectures supporting electronic signatures and audit trails. The sensor meets biocompatibility requirements per ISO 10993-5 (cytotoxicity) and ISO 10993-10 (irritation/sensitization).

Software & Data Management

Data acquisition is performed via the Thermo Scientific TruFluor Optical Reader module, which communicates digitally over RS-485 or Ethernet/IP to process automation systems. Raw fluorescence intensity ratios are converted to pH values using embedded polynomial calibration curves stored in sensor-specific EEPROM. All measurements include timestamping, temperature compensation (via integrated Pt1000 thermistor), and uncertainty estimation per GUM (Guide to the Expression of Uncertainty in Measurement). When paired with BioCommand™ software, users gain access to GLP/GMP-compliant features including role-based access control, configurable alarm thresholds, electronic batch records, and 21 CFR Part 11–compliant audit logs—including operator identity, parameter changes, and calibration event history.

Applications

• Real-time pH monitoring in disposable bioreactors for monoclonal antibody (mAb) production
• Process analytical technology (PAT) implementation for Quality by Design (QbD) workflows in clinical- and commercial-scale manufacturing
• High-throughput clone screening during upstream development using micro-bioreactor arrays
• Continuous perfusion culture where electrode fouling and recalibration frequency limit conventional sensors
• Regulatory submissions requiring documented sensor qualification per ICH Q2(R2) for analytical procedure validation

FAQ

Is the TruFluor pH sensor suitable for steam-in-place (SIP) or autoclave sterilization?
No—this is a single-use, gamma-irradiated sensor intended for pre-sterilized installation only. It is not rated for thermal sterilization cycles.
Can the sensor be reused after a single bioreactor run?
No. The TruFluor pH sensor is designed for one-time use per bioreactor campaign and must be discarded after vessel disposal per biohazard waste protocols.
What is the typical measurement uncertainty across the working range?
At 25 °C and pH 6.8–7.4, the expanded uncertainty (k=2) is ±0.05 pH units, as verified per ISO/IEC 17025-accredited calibration reports provided with each lot.
Does the sensor require field calibration prior to use?
No—each unit ships with factory calibration data written to onboard memory; zero-point and slope verification are optional and supported via Thermo Scientific Calibration Verification Kits (Cat. No. TRU-CAL-VER).
How is sensor performance qualified for regulatory filings?
Thermo Scientific provides a comprehensive Sensor Qualification Package (SQP), including Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ) templates aligned with ASTM E2500-13 and Annex 11 of EU GMP Guidelines.