PCT application · Fully digital biosensor platform

Bring biological testing out of the lab.

BacMan couples a target-specific gold electrode to a low-cost digital reader. The first biological application—E. coli detection for a water-testing pathway—was demonstrated on 27 August 2026 in Stellenbosch, with an independent PalmSens electrical control.

See the measured resultThe next breakthrough test
STELLENBOSCH · 27 AUGUST 2026
≈60 kHz

Absolute magnitude of the baseline-corrected differential frequency shift in BacMan Test 4 after exposure to E. coli.

Independent check: PalmSens4 measured a 62.5% drop in low-frequency IDE impedance in Test 4.

Different measurement methods; their signal sizes are not directly comparable.
One digital reader. Target-specific gold sensors. Local measurement without AI or cloud dependency.Category A · Prototype validation
01 / The biological proof

A real signal, measured two ways.

Phage-coated interdigitated electrodes were transferred from a sterile 2% sucrose reference medium to an E. coli suspension. BacMan measured the response continuously; PalmSens4 separately measured the sensor surface by impedance spectroscopy.

≈60 kHzBacMan differential response magnitude, Test 4
62.5%PalmSens4 impedance decrease at 0.50 Hz, Test 4

The result supports the detection principle under these laboratory conditions. It does not yet establish a field-water performance claim, clinical accuracy, specificity or a detection limit.

Actual BacMan Test 4 graph. BIO and DUMMY frequencies separate sharply following transfer at about 625 seconds, with a differential frequency shift of about negative 60 kilohertz.
Actual Test 4 reconstruction from the BacMan Integrated Biological Validation Evaluation Report. Transfer at approximately 625 seconds; the dashed line shows the differential signal. The PalmSens control is a separate impedance measurement.
02 / The platform

Digital precision begins with two signals.

An active sensor carries the biological recognition layer. A passive dummy measures shared background changes. The reader subtracts the two frequency signals, suppressing common environmental drift and noise. A separate reference channel helps monitor the electronics.

ACTIVE

The key meets the lock

A phage-coated gold IDE is the first demonstrated sensor surface. A different target requires a matching recognition layer and its own validation.

PASSIVE

Subtract the background

The dummy channel follows changes shared with the active channel. BIO minus DUMMY isolates the differential response with a baseline-based detection threshold.

DIGITAL

Read the signal in real time

Compact electronics count oscillator frequencies and apply a local baseline-based detection rule. The measurement needs no AI model, internet connection or cloud service.

This architecture is the platform: keep the digital measurement engine and change the recognition chemistry on the gold electrode for another suitable lock-and-key interaction. It can measure offline in remote settings. Each new application still needs its own biological validation and a suitable power, enclosure and sample workflow.

03 / Access and scale

Designed for a radically lower cost per test.

The prototype reader can be assembled with a soldering iron from roughly €30 of readily available electronic parts. Low-cost gold IDEs and local digital measurement could bring targeted biosensing into field and point-of-care workflows.

~€30Off-the-shelf parts for the prototype reader
Low-costGold IDE sensor designed for scalable production
<€5Target total cost per test at scale

The approximately €30 component figure describes a hand-built reader prototype. A functioning test also requires a target-specific gold IDE, recognition coating, quality control and sample procedure. The below-€5 test cost is a scale-up target, not a verified production price.

04 / The next decisive experiment

From E. coli in a controlled medium to E. coli in urine.

The next biological target is a urinary-tract-infection-associated E. coli strain, with the matching BL1 phage on the gold IDE. The question is whether BacMan can distinguish that target in real urine from the urine background and from suitable negative controls.

If the signal remains specific and reproducible, this becomes the foundation for a rapid diagnostic approach for women with suspected urinary tract infection. A proposed clinical pilot would then compare routine urine samples with standard culture.

What this test must establish

  1. Response to the chosen UTI-associated E. coli strain in urine.
  2. Blank urine and non-target controls, including interference from the sample matrix.
  3. Replicates, dilution series, time to result and limit of detection.
  4. Comparison with urine culture in a later, separately agreed clinical pilot.

The BL1 urine experiment and clinical urine pilot are planned next steps. BacMan is not yet a validated urine diagnostic and does not measure antibiotic susceptibility.

BacMan South Africa

A measured biological proof. A reusable digital platform. A focused next application.

The Stellenbosch result establishes a starting point for developing affordable, targeted biosensing in South Africa. The same architecture can be evaluated for new applications whenever an appropriate recognition mechanism can be built on the gold sensor surface.