1. Many things can be published reactively easy, but its practical value is limited. As you well known, NOVELTY is main factor in the peer-reviewed journals. Who is interested in practical values?

2. Who is really interested in determination one-analyte when multi-component (over 1000 analytes) are published and USED in the toxicological, environmental, etc. labs?

3. Chemist are lazy, if they understand i.e. mass spectrometry, they though underestimeted simple techniques ;)

1. Many things can be published reactively easy, but its practical value is limited. As you well known, NOVELTY is main factor in the peer-reviewed journals. Who is interested in practical values?

2. Who is really interested in determination one-analyte when multi-component (over 1000 analytes) are published and USED in the toxicological, environmental, etc. labs?

3. Chemist are lazy, if they understand i.e. mass spectrometry, they though underestimeted simple techniques ;)

We have developed low-cost sensors for both single analysis or arrays for multiple analyses. BUT there are serious hurdles we have found before commercialisation. The biggest hurdle for us is when the R&D money runs out at the prototype stage, which is enough for plenty of papers or a patent but this is a long long way from a product suitable for the marketplace or for a company to have the confidence to invest in the technology. Also, if it's that simple it's often seen as not having scientific merit without serious novelty value (as Piotr pointed out) for publication. Thirdly, and agreeing with Piotr again, analytical chemists prefer what they know and introducing new competitive techniques into analytical labs is incredibly difficult. Being fair on the analytical chemists, they are often working with limits set using the 'classical' techniques and often it is the company management (non-chemists) that pressures them into keeping with these, however flawed, as they are seen as more sound in a legal sense.

I think some of this has to do with several factors.

First, regulatory requirements - people must use an approved method that is recognized by the regulatory agency. These generally involve some kind of chromatography hyphenated to some selective detector.

As Gavin said, the sensor is good for one specific measurement, generally in one specific sample environment. The expensive chromatography-mass spec system can be used for all kinds of different experiments and is relatively inexpensive to adapt to changing needs of an organization once you've made the initial purchase.

Sensors often lack specificity and robustness when faced with real-world samples. Sure they work beautifully in papers, but how often are the sensors demonstrated on real samples (whole blood, unfiltered river water, free open urban atmosphere)??? Not very. This is the number 1 critique of most sensor papers that our graduate students present when going through their course requirements here. They don't get a lot of points for the critique because it is so obvious, but it is a valid critique.

Tied in with this is the fact that sensors are often based on electrochemical measurements, which respond to activity not concentration, and activity is ridiculously hard to control in real samples. It is also very difficult to get a truly specific chemical sensor. For biosensors it is a bit easier to get specificity, especially if you are targeting a specific gene sequence, but even there the complexity of real samples often overwhelms the sensor.

Confidence in the final result is a big reason. Without a highly controlled sample, it is difficult (impossible?) to have absolute confidence that the signal you are seeing from a sensor that only records one or two parameters is due to your analyte, only your analyte, and not some unexpected interfering species that showed up in the sample.

Hyphenated techniques give you this confidence in your result.

James, I agree with you on most points; I started 40 years ago as an electro-analytical chemists. Without huge grants, electrochemistry was one way for “poor” researchers. But always, when I tested a novel developed electrochemical method with real world samples (CRM’s or inter-laboratory comparison studies) I failed. Thus, I lost my interest in electrochemical analysis. My best results in those proficiency testing methods were achieved with isotope dilution analysis or following the old-fashion way of firstly separating and then identifying if possible with a specific detection (to make sure). The question arises, why must we read all those not-working papers taking our valuable time. As experienced analytical chemist, knowing the “secret” drawbacks of many methods, we can avoid spending too much time by reading too naïve and too optimistic papers, but what is with our students and even worse: what about a lot of “investment-banker-like” founded companies relying only on cartoons of naïve ideas? I know plenty of examples, where I wonder why investment money was used for clearly obviously not working ideas. The beneficiary only shows on the many accepted publications in peer reviewed journals…thus, much money has been lost and still will be lost.

Ahh now we get to the true issue... There is lots of money for "nano sensor omics" if you can get those words into a proposal you get lots of money. Why do the funding agencies send money there? Things sound good to policy makers who far too often have far too weak a scientific background.

I was recently at a summit on environmental monitoring. There were several hundred people there, most of whom were sniffing magical sensor dust or something. The most under-represented group there were environmental scientists and analytical chemists who seemed to be outnumbered 15:1 by electrical engineers ans computer scientists. It was disturbing to say the least!!

It is difficult to prove that these single parameter methods are sufficiently selective to avoid bias induced by similar chemicals or matrix effects.

In real environmental samples (soil, sludge, waste water) thousands of chemicals are present together with our analytical target and the matrix effects are always interfering with quantification and on traditional "sophisticated hyphenated instruments" we solve this by isotope labeled standards, standard additions methods etc.

With lab-on-a-chip we don't have these tools. The developers need to learn that the analytical chemists that work with practical analytical work are meet with requirements to prove their results are correct.