Good lord, this is making the twitter round again.
And again, it’s not completely correct.

It’s just a LED and a photodetector?
Yes, what did you expect?
Is it better than a paper strip?
Maybe….

A #Thread https://twitter.com/Foone/status/1301707401024827392

"Naked eye" sensitivity varies a lot from person to person. I can see a faint line, another person don’t see anything.
Thus, it’s not standardised.
It’s biased (I want to see what I want to see)
It’s not quantitative but only qualitative.

You can solve all these problems with a simple LED and a photodetector.
It’s sensitive
It’s reproducible
It’s not biased
It can be used for quantitative analysis.

It obviously depending on how good the detector is. But usually is way better than naked eye.

Pregnancy tests are usually qualitative (yes/no) so the limit of detection is the main important thing.
Sensors >> naked eye

For quantitative (how much stuff is in there) analysis
Sensor >>>>>> naked eye

As the sensor is more sensitive than naked eye, it manage to detect smaller amounts of analytes.
This also means that they require less reagent to detect the same thing.

A proper test would have been done with dilution series and a comparison between naked eye and the sensor use there. In this way you would see the increased sensitivity in the digital pregnancy test compared to your eyes.
Opening it and saying it’s only a LED is reductive.

During the introduction lecture of my course I teach exactly that. Difference between what you can do by eye (easily) and what you cannot

Is it a digital pregnancy test better?
It is more sensitive, reliable, and reproducible for sure. In most of the cases it may be an overkill, I agree on that.
But reducing the digital sensor to a mare “it’s only a LED/detector” it’s wrong.

Source? I teach this stuff -_-

This is another slide I use in the course. Can you see where I’m going?

Naked Eye vs RGB sensor….